Method and apparatus for regulating fluid flow or conserving fluid flow

ABSTRACT

Fluid flow regulators and fluid conservers are disclosed. An exemplary fluid conserver may be operated in one of an intermittent mode of operation and a continuous mode of operation. Further, the exemplary conserver provides at least two pulses of fluid in response to a first trigger, such as the inhalation of a patient.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/548,058, filed Feb. 26, 2004, titled FLOW REGULATOR; U.S. Provisional Patent Application Ser. No. 60/606,288, filed Sep. 1, 2004, titled METHOD AND APPARATUS FOR REGULATING FLUID FLOW OR CONSERVING FLUID FLOW; and U.S. Provisional Patent Application Ser. No. 60/620,890, titled FLUID REGULATOR, filed Oct. 21, 2004, the disclosures of which are expressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The present disclosure relates to devices for regulating the flow of a fluid, such as oxygen, and/or for providing a calibrated flow of the fluid in at least either a continuous mode of operation or in an intermittent mode of operation.

Patients with lung diseases frequently need oxygen delivered to their lungs as part of their therapy. In certain known therapies, a continuous flow of oxygen is supplied to a patient. However, a continuous flow is not required at all times, such as when the patient is exhaling. It is also known to provide oxygen conserving devices that supply oxygen to the patient in an intermittent fashion.

In an illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula includes a body member having a first end, a second end, a central longitudinal axis, an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output. The apparatus also includes a flow selector positioned between the input and the output. The flow selector is rotatably coupled to the body member at a location between the first end and the second end of the body member. The flow selector is actuatable from the exterior of the body member and positioned such that an axis of rotation of the flow selector is parallel to and offset from the central longitudinal axis of the body member. The flow selector illustratively includes a first fluid passage configured to restrict the flow of fluid to a first flow rate from the input to the output when the first fluid passage is aligned with the fluid passage which connects the input and the output.

In another illustrated embodiment of the present invention, an apparatus is provided for coupling a first fluid inlet of a device to a first fluid outlet of the device and a second fluid inlet of the device to a second fluid outlet of the device. The apparatus includes a body member adapted to be rotatably coupled to the device. The body member includes a plurality of fluid passages, each fluid passage being selectably positionable in fluid communication with the first fluid inlet and the first fluid outlet by rotating the body member relative to the device. Each fluid passage is configured to provide a respective flow rate of fluid from the first fluid inlet to the first fluid outlet when positioned in fluid communication with the first fluid inlet and the first fluid outlet. The apparatus also includes an axle coupled to the body member. The axle has a central fluid passage in fluid communication with the second fluid inlet and the second fluid outlet to provide a flow of fluid from the second fluid inlet to the second fluid outlet.

In another illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula for communication of fluid to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output. The apparatus also includes a pneumatic controller including a valve assembly in communication with the fluid passage of the body. The pneumatic controller is configured to detect an inhalation of the patient and to provide a series of at least two pulses of the fluid to the output during the inhalation of the patient. The pneumatic controller provides an initial pulse having a fluid amplitude greater than a fluid amplitude of subsequent pulses in the series of at least two pulses without the aid of a fluid reservoir separate from the fluid passage of the body.

In yet another illustrated embodiment of the present invention, an apparatus for providing fluid from a source of pressurized fluid to a patient includes a single lumen cannula configured to be received by the nostrils of the patient, and a body having an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output. The apparatus also includes a flow selector having at least a first fluid passage configured to provide a first restricted fluid flow rate and a second fluid passage configured to provide a second restricted fluid flow rate, each of the first fluid passage and the second fluid passage being selectably positionable in the fluid passage of the body between the input and the output. The apparatus also includes a controller configured to detect a first trigger corresponding to a beginning portion of an inhalation of the patient and a second trigger corresponding to one of an ending portion of the inhalation of the patient and an exhalation of the patient. The controller is further configured to provide fluid to the cannula through the output between the detection of the first trigger and the detection of the second trigger.

In still another illustrated embodiment of the present invention, a method for conserving fluid supplied to a patient comprising the steps of coupling the patient to a source of pressurized fluid with a single lumen cannula and a conserver configured to provide fluid to the patient at at least a first pressure, the first pressure being less than the pressure of the fluid in the source of pressurized fluid. The method also includes selecting a fluid flow setting from a plurality of discrete fluid flow settings, detecting a first trigger corresponding to a beginning of a first inhalation of the patient, providing a first pulse of fluid to the patient, providing subsequent pulses of fluid to the patient until the detection of a second trigger corresponding to one of an ending of the first inhalation of the patient and a first exhalation of the patient, and preventing the flow of fluid to the patient until the detection of a first subsequent trigger corresponding to a beginning of a second inhalation of the patient.

In another illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid, an output adapted to be coupled to the cannula, and a fluid passage configured to connect the input to the output. The apparatus also includes a flow selector having at least a first fluid passage configured to provide a first restricted flow rate of fluid and a second fluid passage configured to provide a second restricted flow rate of fluid, each of the first fluid passage and the second fluid passage being positionable in the fluid passage of the body between the input and the output to provide a first flow setting and a second flow setting respectively, the flow selector being positionable in the first flow setting or the second flow setting by an operator from an exterior of the body. The apparatus further includes a controller configured to provide fluid to the cannula based on the respective flow setting of the flow selector. The controller is operable in two modes of operation, a continuous mode of operation wherein fluid is provided to the cannula in a continuous flow and an intermittent mode of operation wherein the fluid is provided to the cannula as multiple pulses of fluid. The apparatus still further includes a mode selector accessible from the exterior of the body and actuatable by an operator independent of an actuation of the flow selector, the mode selector having a first mode setting and a second mode setting, the mode selector being operably coupled to the controller and configured such that the first mode setting configures the controller to operate in the continuous mode of operation and the second mode setting configures the controller to operate in the intermittent mode of operation.

In another illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid and an output adapted to be coupled to the cannula and a fluid passage configured to connect the input to the output. The apparatus also includes a flow selector having a plurality of flow settings, each flow setting corresponding to a respective flow rate of fluid when positioned in the fluid passage, and a controller means for controlling the provision of fluid to the cannula as multiple pulses of fluid, a first pulse being provided in response to a first trigger corresponding to the beginning of a reduction in pressure in the cannula and a second pulse prior to a second trigger.

In another illustrated embodiment of the present invention, an apparatus is provided for coupling a first fluid passage of a device to a second fluid passage of a device, the apparatus being configured to provide fluid flow from the first fluid passage to the second fluid passage. The apparatus includes an axle adapted to be coupled to the device, and a body member coupled to the axle and configured to be rotatable relative to the device. The body member includes a plurality of fluid passages, each fluid passage having a first portion generally positionable in fluid communication with the first fluid passage of the device and a second portion generally positionable in fluid communication with the second fluid passage of the device, each fluid passage being selectably positionable in fluid communication with the first fluid passage and the second fluid passage by rotating the body member relative to the device, each fluid passage configured to provide a respective flow rate of fluid from the first fluid passage to the second fluid passage when positioned in fluid communication with the first fluid passage and the second fluid passage, and each fluid passage being configured such that one of the first portion and the second portion remains in fluid communication with the respective one of the first fluid passage and the second fluid passage longer than the other of the first portion and the second portion remains in fluid communication with the other of the respective first fluid passage and the second fluid passage during the movement of the respective fluid passage out of fluid communication with the first fluid passage and the second fluid passage.

In another illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid, an output adapted to be coupled to the cannula, and a fluid passage configured to connect the input to the output, the fluid passage including a seat for receiving a seal. The apparatus also includes a flow selector having at least a first fluid passage configured to provide a first restricted flow rate of fluid and a second fluid passage configured to provide a second restricted flow rate of fluid. Each of the first fluid passage and the second fluid passage are positionable in the fluid passage of the body between the input and the output. The apparatus further includes a pneumatic controller including a piston moveably coupled to the body and configured to move between a first position preventing the passage of fluid to the outlet and a second position permitting the passage of fluid to the outlet, the movement of the piston between the first position and the second position being controlled to provide an intermittent flow of fluid to the outlet, wherein a first portion of the piston contacts and cooperates with the seal to prevent the passage of fluid to the outlet in the first position and wherein the first portion is spaced apart from the seal to permit the passage of fluid to the outlet in the second position.

In another illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid and an output adapted to be coupled to the cannula and a fluid passage configured to connect the input to the output, the body including at least three body portions which when assembled form the body, the at least three body portions being keyed to permit the assembly of the body portions in a single orientation. The apparatus also includes a coupler configured to couple the at least three body portions together, and a flow selector coupled to the body and positioned such that an outer surface of the flow selector is actuatable by an operator, the outer surface of the flow selector being positioned between a first end of the body and a second end of the body. The flow selector has at least a first fluid passage configured to provide a first restricted flow rate of fluid and a second fluid passage configured to provide a second restricted flow rate of fluid, each of the first fluid passage and the second fluid passage being positionable in the fluid passage of the body between the input and the output. The apparatus further includes a controller configured to provide fluid to the output at least in an intermittent mode of operation, wherein the fluid is provided as multiple pulses of fluid during an inhalation of the patient.

In another illustrated embodiment of the present invention, an apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid and an output configured to be coupled to the cannula and a fluid passage configured to connect the input to the output. The apparatus also includes a flow selector rotatably coupled to the body and having a first outer surface at least partially concealed within the body. The flow selector includes a plurality of fluid passages, each of the plurality of fluid passages being configured to restrict the flow of fluid from the input to the output by a respective amount when the respective fluid passage is aligned with the fluid passage, wherein the selection of a first fluid passage from the plurality of fluid passages is performed by a rotation of the flow selector, the rotation being imparted by an operator applying a force to a portion of the first outer surface of the flow selector which is accessible from an exterior of the body.

In another illustrated embodiment of the present invention, an apparatus is provided for use with a fluid apparatus including a body having an interior cavity, a fluid inlet which is configured to receive a high pressure fluid from a source of pressurized fluid, and an application device which utilizes fluid at a lower pressure, wherein the apparatus is configured to provide fluid for the application device at the lower pressure. The apparatus includes a base member adapted to be received within the interior cavity of the fluid apparatus, the base member including a base portion and a guide portion extending from the base portion. The base member has a central passageway extending there through, the central passageway being positioned such that it is in fluid communication with the fluid inlet of the fluid apparatus. The apparatus also includes a piston adapted to be received within the interior cavity of the fluid apparatus, the piston including a piston base portion and a stem portion, the stem portion being configured to be received by the central passageway in the guide portion of the base member. The piston has a fluid passageway there through with a fluid inlet in the stem portion and a fluid outlet in the piston base portion. The fluid outlet is in fluid communication with the application device. The apparatus further includes a spring sized to receive the guide portion of the base member, a first end of the spring being positioned adjacent the base portion of the base member and a second end of the spring being positioned adjacent a seat surface of the piston base portion, the seat surface being located in a recess of the piston base portion, the recess being sized to receive a first end of the guide portion of the base member.

In another illustrated embodiment of the present invention, an apparatus for providing fluid from a source of pressurized fluid to a cannula for communication to a patient includes a body having an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output. The apparatus also includes a pneumatic controller being operable in two modes of operation, a continuous mode of operation wherein fluid is provided to the cannula in a continuous flow and an intermittent mode of operation wherein the fluid is provided to the cannula as multiple pulses of fluid a time period generally between the detection of a first trigger and a second trigger. The apparatus further includes a mode selector accessible from the exterior of the body and actuatable by an operator. The mode selector has a first mode setting and a second mode setting, the mode selector being operably coupled to the pneumatic controller and configured such that the first mode setting configures the pneumatic controller to operate in the continuous mode of operation and the second mode setting configures the pneumatic controller to operate in the intermittent mode of operation.

Additional, features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an exemplary flow regulator coupled to a source of pressurized fluid and an application device, the flow regulator having a flow selector.

FIG. 2 is a sectional view of the flow regulator of FIG. 1 coupled to a source of pressurized fluid, illustratively a source of pressurized oxygen, and a fluid conserver, illustratively an oxygen conserver.

FIG. 3A is a back view of an exemplary flow selector including a flow restrictor and a knob.

FIG. 3B is a front view of the flow restrictor and knob of the flow selector of FIG. 3A.

FIG. 4A is a sectional view of the exemplary flow selector of FIG. 3A and an associated axle.

FIG. 4B is a sectional view of the flow selector of FIG. 3A and an exemplary associated axle having a central passage.

FIG. 5A is a back view of another exemplary flow selector showing an outer knob portion and an inner flow restrictor having a plurality of flow passages, each one of the fluid passages being configured to provide a calibrated amount of fluid flow and showing a plurality of depressions for receiving a detent member (such as the detent member of FIG. 19) and a central passage for receiving an axle (such as the axle of FIG. 19).

FIG. 5B is a sectional view of the flow selector of FIG. 5A showing a first one of a plurality of flow calibrators positioned within openings in a side wall of the outer knob portion.

FIG. 5C is a front view of the flow selector of FIG. 5A.

FIG. 5D is a diagrammatic representation of a second exemplary configuration of the fluid passages of the inner flow selector, the fluid passages having a first portion offset from a second portion.

FIG. 6A is a sectional view of an exemplary flow regulator incorporating the flow selector of FIG. 3A and an exemplary fluid inlet retainer and pressure reduction section, the flow regulator being coupled to a source of pressurized fluid and an application device.

FIG. 6B is a sectional view of the flow regulator of FIG. 6A coupled to an oxygen conserver.

FIG. 6C is an enlarged view of the exemplary fluid inlet retainer and pressure reduction section of FIG. 6A.

FIG. 7 is an isometric unassembled view of a vent mechanism, a biasing member, a piston, and a housing of the pressure reduction section of FIG. 6A.

FIG. 8 is an isometric assembled view of the vent mechanism, biasing member, and piston of the pressure reduction section of FIG. 6A.

FIG. 9 is an end view of the flow regulator of FIG. 6A including the flow selector of FIG. 5A and an axle with a central fluid passage.

FIG. 10 is an isometric view of an exemplary conserving device including an exemplary flow regulator or regulating portion coupled with an exemplary fluid conserver application device or conserving portion, the flow regulator including a body portion and the fluid conserver application device including a first body portion, a second body portion, and a third body portion.

FIG. 11 is a side isometric view of the conserving device of FIG. 10 showing a thumb wheel for selecting a predetermined flow rate and a pressure gauge.

FIG. 12 is a top view of the conserving device of FIG. 10.

FIG. 12A is a top view of the assembly of FIG. 12 with various features shown.

FIG. 12B is a cross section of FIG. 12A taken along lines 12B-12B in FIG. 12A.

FIG. 12C is a cross section of FIG. 12A taken along lines 12C-12C in FIG. 12A.

FIG. 12D is a cross section of FIG. 12A taken along lines 12D-12D in FIG. 12A.

FIG. 13 is a sectional view of the conserving device of FIG. 10 illustrating the various components of the conserving device of FIG. 10.

FIG. 14 is a detail view of the sectional view of FIG. 13.

FIG. 14A is a detail view of the sectional view of FIG. 13 illustrates the conserving device of FIG. 14 in a start-up orientation and configured for operation in the intermittent mode of operation.

FIG. 14B illustrates the movement of the demand piston in the fluid conserving device to prevent the flow of fluid to the nipple and hence to the cannula due to a build-up of fluid behind the demand piston.

FIG. 14C illustrates the movement of the diaphragm in response to a trigger event, illustratively a patient inhalation, thereby relieving the build-up of fluid behind the demand piston resulting in the subsequent movement of the demand piston to permit the flow of fluid to the nipple and hence to the cannula.

FIG. 14D illustrates the orientation of the components of the fluid conserving device when the fluid conserving device is in the continuous mode of operation.

FIG. 15 shows exemplary pulses of fluid being provided by the conserving device of FIG. 10 relative to an exemplary breathing cycle of a patient connected to a single lumen cannula.

FIG. 15A is a comparison of the fluid pulses of three commercial conservers.

FIG. 16 is an isometric view of the body portion of the flow regulator of FIG. 10, showing an internal cavity and showing an exemplary pressure reduction assembly which is to be placed in the internal cavity of the first body portion of the flow regulator of FIG. 10, the pressure reduction assembly being held in the internal cavity with a retainer.

FIG. 17A is a first exemplary side view of the body portion of the flow regulator of FIG. 10.

FIG. 17B is a second exemplary side view of the body portion of the flow regulator of FIG. 10.

FIG. 17C is a third exemplary side view of the body portion of the flow regulator of FIG. 10.

FIG. 17D is a fourth exemplary side view of the body portion of the flow regulator of FIG. 10.

FIG. 18 is an isometric view of the pressure reduction section of FIG. 16 assembled to the body portion of the flow regulator.

FIG. 19 is an exploded isometric view of the body portion of the flow regulator of FIG. 17 with the pressure reduction assembly of FIG. 16 assembled thereto and a detent, a biasing member, the flow selector of FIG. 5A, a retainer for the flow selector and associated seal.

FIG. 20 is an isometric view of the body portion of the flow regulator of FIG. 10 having the pressure reduction assembly of FIG. 16 and the flow selector of FIG. 5A assembled.

FIG. 21A is a bottom view of a first body portion of the fluid conserver application device generally showing a nipple adapted for connection to a single lumen cannula and a needle valve exploded therefrom, the needle valve being positionable with a recess of the first body portion.

FIG. 21B is a top view of the first body portion of FIG. 21A.

FIG. 22 is a generally isometric view of the first body portion of the fluid conserver application device assembled onto the assembly of FIG. 20.

FIG. 23A is an exploded assembly view of the second body portion of FIG. 22, showing a first mode selector member, a second mode selector member, a demand piston and a biasing member, the demand piston generally used in the controlling of the delivery of pulses of fluid from the fluid conserver application device to a cannula and hence to the patient.

FIG. 23B is a side view of the demand piston and biasing member of FIG. 23A.

FIG. 24 is an assembled view illustrating the first mode selector member, the second mode selector member, the demand piston, and the biasing member assembled to the assembly of FIG. 22.

FIG. 25A is a front view of an exemplary second body portion of the fluid conserver application device.

FIG. 25B is a back view of the second body portion of FIG. 25A.

FIG. 25C is a sectional view of the second body portion generally taken along lines 25C-25C in FIG. 25B.

FIG. 25D is a sectional view of the second body portion of FIG. 25A generally taken along lines 25D-25D in FIG. 25B.

FIG. 26 is an isometric view showing the second body portion of the fluid conserver application device assembled with the assembly of FIG. 24.

FIG. 27 is a bottom view of the bottom of the third body portion of the fluid conserver application device of FIG. 10 with the diaphragm of FIG. 28 assembled thereto.

FIG. 27A is a sectional view of the assembly of the third body portion and diaphragm of FIG. 27 taken along lines 27A-27A of FIG. 27.

FIG. 28 is an exploded isometric view of a diaphragm assembly including a diaphragm and a support.

FIG. 29 is an exploded isometric view of the third body portion of FIG. 27, the diaphragm assembly of FIG. 28, and the assembly of FIG. 26.

FIG. 30A is a bottom isometric view of a modified third body portion of the fluid conserver application device configured for use with a dual lumen cannula.

FIG. 30B is a top isometric view of a dual lumen cannula third body portion.

FIG. 31 is an exploded assembly of a modified second body portion of the fluid conserver application device to include an interlock member.

FIG. 32 is a bottom isometric view of the bottom side of a modified second mode selector member of FIG. 23 configured to interact with the interlock member of FIG. 31.

FIG. 33 is a bottom isometric view of the second body portion of FIG. 31 with the interlock member assembled thereto.

FIG. 34 shows a modified version of the flow selector member of FIG. 5A configured to interact with the interlock member of FIG. 31.

DETAILED DESCRIPTION

Referring to FIG. 1, a flow regulator 100 is shown. Flow regulator 100 includes a body 102 having a fluid inlet passage 104 and a fluid outlet passage 106. Fluid inlet 104 may be coupled to a source of pressurized fluid 108. Fluid outlet 106 may provide a continuous flow of fluid or may be coupled to an application device 110. Example application devices include fluid conserver devices, fluid regulators, flow control valves, and tubing to transport the fluid. In one embodiment, application device 110 is at least partially contained within body 102. In another embodiment, application device 110 is not contained within body 102.

FIG. 2 illustrates flow regulator 100 of FIG. 1 having fluid inlet passage 104 coupled to a source of pressurized oxygen 109 and fluid outlet passage 106 coupled to an oxygen fluid conserver application device 111. In one embodiment, oxygen conserver 111 is a pneumatic oxygen conserver. An exemplary pneumatic oxygen conserver and variations thereof are shown in FIGS. 10-14 and 16-34. In another embodiment, oxygen conserver 111 is an electronic oxygen conserver.

Referring to FIG. 1, body 102 is shown as a revolved cylinder having a central axis 112. In alternative embodiments, body 102 is another revolved section, includes other revolved sections, is a non-revolved section such as rectangular or square, or a combination of revolved sections and/or non-revolved sections. In one embodiment, body 102 is a one piece housing. In another embodiment, body 102 includes at least two sections which are assembled together.

Fluid inlet passage 104 and fluid outlet passage 106 are shown as being generally cylindrical passageways which are coaxial with central axis 112. In alternative embodiments, fluid inlet passage 104 and/or fluid outlet passage 106 may have other transverse sectional shapes and may be comprised of more complex passageways. For example, fluid outlet passage 106 may comprise a first portion 106 a which is coaxial with central axis 112 and a second portion 106 b which is perpendicular to central axis 112, first portion 106 a and second portion 106 b intersecting to form fluid outlet passage 106. Further, fluid inlet passage 104 and fluid outlet passage 106 may have additional components intersecting with the respective one of fluid inlet passage 104 and fluid outlet passage 106. For example, a pressure reduction section, such as pressure reduction section 170 shown in FIG. 7, to reduce the pressure of the fluid received from source 108 or a fluid pressure gauge, such as gauge 334 shown in FIG. 6A, may be interposed in fluid inlet passage 104.

Flow regulator 100 further includes a flow selector 114. Flow selector 114 is coupled to body 102 and includes at least one fluid passage or opening 116 sized to permit a known or calibrated flow rate of fluid to pass from fluid inlet passage 104 to fluid outlet passage 106. Fluid passage 116 provides the known or calibrated flow rate of fluid by restricting the amount of fluid that passes from fluid inlet passage to fluid outlet passage.

As shown in FIG. 1, flow selector 114 is rotatably coupled to body 102 and is rotatable about an axis 117 in directions 118, 120. Axis 117 is generally parallel with central axis 112 and offset from central axis 112. In the illustrated embodiment, flow selector 114 includes a plurality of openings 116, openings 116 a and 116 b being shown. Preferably openings 116 a and 116 b are sized to permit different known or calibrated flow rates of fluid to pass from fluid inlet passage 104 to fluid outlet passage 106 such that by rotating flow selector 114 in one of directions 118, 120 the operator may select a first known or calibrated flow rate from a plurality of known or calibrated flow rates.

In one embodiment, a surface 122 of flow selector 114 is accessible from the exterior of body 102. Preferably, surface 122 is raised relative to a surface 124 of body 102 such that a user can easily locate flow selector 114 and impart a rotation to flow selector 114 in one of directions 118, 120. Even though surface 122 of flow selector 114 is raised relative to surface 124 of body 102, flow selector 114 is substantially within an envelope of body 102 defined by surface 124. In alternative embodiments, surface 122 is generally flush with surface 124 (touching the envelope of body 102) or recessed relative to surface 124 (within the envelope of body 102). In one embodiment, surface 122 is textured, such as a knurled surface, to aid in gripping.

In one embodiment, flow selector 114 includes a detent (not shown) that aids the user in aligning one of the plurality of openings 116 with fluid inlet passage 104 and fluid outlet passage 106. The detent biases the flow selector 114 to a rotational position corresponding to the alignment of one of the plurality of openings 116 with fluid inlet passage 104 and fluid outlet passage 106

Referring to FIGS. 3 and 4, an exemplary flow selector 200 is shown. Flow selector 200 includes a knob 202, a flow restrictor 204, and a seal 206 (see FIG. 4A) positioned between knob 202 and flow restrictor 204. Knob 202 includes a recess 208 sized to receive flow restrictor 204. Recess 208 includes a key member 209 (see FIG. 3A) which is received by key slot 210 (see FIG. 3A) of flow restrictor 204. Key member 209 and key slot 210 cooperate to align flow restrictor 204 relative to knob 202 such that fluid passages 214 in knob 202 are aligned with fluid passages 216 in flow restrictor 204.

It should be appreciated that knob 202 and flow restrictor 204 may be made as an integral component thereby obviating the need for seal 206. However, by having flow restrictor 204 and knob 202 be separate components, different flow restrictors 204 may be used with knob 202 to provide greater flexibility in the range of flow rates flow selector 200 is configured to generate.

In one embodiment, flow restrictor 204 is press fit into recess 208 of knob 202. In another embodiment, flow restrictor 204 is coupled to knob 202 by a coupler (not shown). In still another embodiment, flow restrictor 204 and knob 202 are each press fit onto an axle 220. If flow restrictor 204 and knob 202 are press fit onto axle 220, axle 220 is rotatably coupled to body 102 such that axle 220 and flow selector 200 are rotatable about axis 117 in directions 118, 120. In another embodiment, flow selector 200 is rotatable relative to axle 220 and axle 220 is fixably coupled to body 102.

Referring to FIG. 4A, knob 202 includes a first radial extent defined generally by first outer surface 222 and a second radial extent defined generally by second outer surface 224. First outer surface 222 is configured to be gripped by a user such that the user is able to impart a rotation of flow selector 200 about axis 117 in one of directions 118, 120. In one embodiment, first outer surface 222 is textured, such as knurled, to facilitate the gripping of surface 222 by a user.

In one embodiment, knob 202 including surface 222 is made from aluminum. In other examples, knob 202 including surface 222 is made from brass or other suitable materials. In another embodiment, knob 202 is made from a first material, such as aluminum, brass, or a thermoplastic material, and surface 222 is made of a different second material, the second material aiding in the gripping of surface 222. In one example, knob 202 is made of thermoplastic material, such as ABS, and surface 222 is made from a rubber material. Surface 222 is created by molding the base of knob 202 out of ABS and coupling the rubber material to the ABS material. In one example, the ABS knob is an insert in a mold and the rubber material is molded over the ABS knob.

Second outer surface 224 has a smaller diameter than first outer surface 222. Second outer surface 224 is configured to include indicia (not shown) indicating which pair of passages 214 and respective passage 216 are aligned with fluid inlet 104 and fluid outlet 106 and therefore to indicate the selected flow rate. In one example, indicia are molded onto surface 224. In a further example, the indicia are embossed. In another example, the indicia are recessed. In yet another example, the indicia are painted or otherwise applied to surface 224, such as with one or more stickers.

It should be appreciated that any suitable indicia may be used, such as lines, numbers, or letters. In one example, body 102 includes indicia on surface 124, such as a line or a plurality of numbers. The user of flow regulator 100 aligns the appropriate indicia of flow selector 200 with the indicia on body 102 to select the respective flow rate. In one example, body 102 includes a line as an indicia and flow selector 200 includes a plurality of numbers, each number corresponding to a respective flow rate, such that by aligning a number on flow selector 200 with the line on body 102 results in the corresponding passages 214 and 216 being aligned with fluid inlet 104 and fluid outlet 106. In another example, body 102 includes a plurality of numbers as an indicia and flow selector 200 includes a line, such that by aligning the line of flow selector 200 with a number on body 102 results in the corresponding passages 214 and 216 being aligned with fluid inlet 104 and fluid outlet 106. In still a further example, body 102 includes a window, such as window 380 shown in FIG. 11 and flow selector 200 includes a plurality of numbers, such as number 2 shown in FIG. 11, such that aligning a number of flow selector 200 with the window on body 102 results in the corresponding passages 214 and 216 being aligned with fluid inlet 104 and fluid outlet 106.

Referring to FIG. 4A, knob 202 further includes a seat 230 sized to receive seal 206. Seal 206 is inserted into recess 208 of knob 202 such that a first side 236 of seal 206 contacts step 230 of knob 202. Next, flow restrictor 204 is inserted into recess 208 such that a first end 240 of flow restrictor 204 contact a second side 238 of seal 206.

Seal 206 includes a plurality openings 232 each located to correspond to one of passages 214 of knob 202 and the respective one of passages 216 of flow restrictor 204. It should be noted that openings 232 do not overlap, but are separated by a land (not shown). As such, seal 206 prevents fluid escaping from a respective pair of passages 214, 216 to another one of passages 214, 216.

Referring to FIGS. 3A, 3B, and 4A, an exemplary embodiment of flow restrictor 204 is shown. In one embodiment, flow restrictor 204 is made from brass. The illustrated embodiment of flow resistor 204 includes seven fluid passages, 216 a-g, each one corresponding to a respective flow rate. In one embodiment, the passages 216 are arranged in order of increasing flow rates. For example, passage 216 a corresponds to a flow rate of 0.5 liters of fluid per minute (lpm), passage 216 b corresponds to a flow rate of 1.0 lpm, passage 216 c corresponds to a flow rate of 2.0 lpm, passage 216 d corresponds to a flow rate of 3.0 lpm, passage 216 e corresponds to a flow rate of 4.0 lpm, passage 216 f corresponds to a flow rate of 5.0 lpm, and passage 216 g corresponds to a flow rate of 6.0 lpm.

Referring to FIG. 4A, each passage 216 includes a first portion 242 and a second portion 244 including an orifice 246. Each orifice 246 is sized to correspond to the flow rate of the respective passage 216. In the illustrated embodiment, first portion 242 has a larger radial extent than second portion 244. In another embodiment, first portion 242 and second portion 244 have the same radial extent.

Referring to FIGS. 3A and 4A, flow restrictor 204 includes a plurality of indexes or recesses 250 which cooperate with a detent, such as ball 554 in FIG. 19. Indexes 250 are positioned such that each one corresponds to the alignment of a respective combination of passage 214 and passage 216 with fluid inlet passage 104 and fluid outlet passage 106. In another embodiment, indexes 250 are bumps which cooperate with depressions on body 102.

Referring to FIG. 4A, knob 202 further includes a recess 256 and a recess 258, each sized to receive a seal 260 (see FIG. 6A). Seal 260 generally seals the region between knob 202 and body 102 to prevent dust or other particles from entering flow regulator 100. In one embodiment, seal 260 is made from a polymeric material, such as Teflon or Kel-F. Additional seals may be provided to provide a fluid tight seal between fluid inlet passage 104 and flow selector 200 and fluid outlet passage 106 and flow selector 200. For example, o-ring seals 262 are shown in FIG. 6A positioned between fluid inlet passage 104 and flow selector 200.

Referring to FIG. 4B, an alternative axle 220′ is shown assembled with knob 202 resulting in flow selector 200′. Axle 220′ differs from axle 220 of FIG. 3A in that axle 220′ includes a central passage 221 for transporting fluid. Therefore, a second fluid inlet passage (not shown) may be coupled to a first end 223 of axle 220′ and a second fluid outlet passage (not shown) may be coupled to a second end 225 of 220′ to provide a second flow of fluid through central passage 221 which bypasses flow passages 216 in flow restrictor 204. As such, the combination of flow selector 200 and axle 220′ permits a metered or restricted flow of fluid based the calibration of respective passages 214 and 216 through flow selector 200 and a second flow of fluid through central passage 221 of axle 220′ which bypasses flow passages 214 and 216. Example uses for the second flow of fluid include providing a continuous flow line to the patient, such as for a fluid conserver, and/or to provide a fluid supply for the operation of an application device, such as providing pressure to one side of a diaphragm of a pneumatic fluid conserver application device.

Referring to FIGS. 5A-5C another exemplary embodiment of a flow selector 400 is shown. Flow selector 400 is generally similar to flow selector 200 and includes a knob 402 and a flow restrictor 404. Knob 402 includes an opening 408 sized to receive flow restrictor 404. Opening 408 may include a key member (not shown) which is received by key slot (not shown) of flow restrictor 404. Key member (not shown) and key slot (not shown) cooperate to align flow restrictor 404 relative to knob 402 such that indicia on knob 402 are aligned with flow restrictor 404.

Unlike knob 202, knob 402 does not include a plurality of fluid passages. As such, a seal is not required between knob 402 and flow restrictor 404. It should be appreciated that knob 402 and flow restrictor 404 may be made as an integral component. However, by having flow restrictor 404 and knob 402 be separate components, different flow restrictors 404 may be used with knob 402 to provide greater flexibility in the range of flow rates flow selector 400 is configured to generate.

In one embodiment, flow restrictor 404 is press fit into opening 408 of knob 402. In another embodiment, flow restrictor 404 is coupled to knob 402 by a coupler (not shown). In still another embodiment, flow restrictor 404 is press fit onto an axle, such as axle 220 or axle 220′ and knob 402 is press fit onto flow restrictor 404. If flow restrictor 404 and knob 402 are press fit onto an axle, such as axle 220 or axle 220′, then axle 220 or 220′ is rotatably coupled to body 102 such that axle 220 or 220′ and flow selector 400 are rotatable about axis 117 in directions 118, 120. In another embodiment, flow selector 400 is rotatable relative to axle 220 or axle 220′ and axle 220 or axle 220′ is fixably coupled to body 102.

Knob 402 similar to knob 202 includes a first radial extent defined generally by first outer surface 422 and a second radial extent defined generally by second outer surface 424. First outer surface 422 is configured to be gripped by a user such that the user is able to impart a rotation of flow selector 400 such as about axis 117 in one of directions 118, 120 when flow selector 400 is used with body portion 102. In one embodiment, first outer surface 422 is textured, such as knurled, to facilitate the gripping of surface 422 by a user.

In one embodiment, knob 402 including surface 422 is made from aluminum. In other examples, knob 402 including surface 422 is made from brass or other suitable materials. In another embodiment, knob 402 is made from a first material, such as aluminum, brass, or a thermoplastic material, and surface 422 is made of a different second material, the second material aiding in the gripping of surface 422. In one example, knob 402 is made of thermoplastic material, such as ABS, and surface 422 is made from a rubber material. Surface 422 is created by molding the base of knob 402 out of ABS and coupling the rubber material to the ABS material. In one example, the ABS knob is an insert in a mold and the rubber material is molded over the ABS knob.

Second outer surface 424 has a smaller diameter than first radial surface 422. Second outer surface 424 is configured to include indicia, such as indicia 509 in FIG. 11, indicating which of passages 416 of flow restrictor 404 are aligned with fluid inlet 104 and fluid outlet 106 and therefore to indicate the selected flow rate. In one example, indicia are molded onto surface 424. In another example, the indicia are embossed. In yet another example, the indicia are recessed. In a further example, the indicia are painted or otherwise applied to surface 424, such as with one or more stickers.

It should be appreciated that any suitable indicia may be used, such as lines, numbers, or letters. In one example, body 102 includes indicia on surface 124, such as a line or a plurality of numbers. The user of flow regulator 100 aligns the appropriate indicia of flow selector 400 with the indicia on body 102 to select the respective flow rate. In one example, body 102 includes a line as an indicia and flow selector 400 includes a plurality of numbers, each number corresponding to a respective flow rate, such that by aligning a number of flow selector 400 with the line on body 102 results in the corresponding passage 414 being aligned with fluid inlet 104 and fluid outlet 106. In another example, body 102 includes a plurality of numbers as an indicia and flow selector 400 includes a line, such that by aligning the line of flow selector 400 with a number on body 102 results in the corresponding passage 416 being aligned with fluid inlet 104 and fluid outlet 106. In still a further example, body 102 includes a window, such as window 380 shown in FIG. 11 and flow selector 400 includes a plurality of numbers, such as number 2 shown in FIG. 24, such that aligning a number of flow selector 400 with the window on body 102 results in the corresponding passage 416 of flow restrictor 404 being aligned with fluid inlet 104 and fluid outlet 106.

Referring to FIGS. 5A, 5B, and 5C, an exemplary embodiment of flow restrictor 404 is shown. In one embodiment, flow restrictor 404 is made from brass. The illustrated embodiment of flow resistor 404 includes five fluid passages, 416 a-e in FIGS. 5A-C, each one corresponding to a respective flow rate. In another embodiment, flow restrictor 404 includes six fluid passages 416. As stated above in connection with flow restrictor 204, multiple fluid passages 416 are configured to provide different flow rates. In one embodiment, fluid passages 416 are arranged in increasing order of flow rates. For example, passage 416 a corresponds to a flow rate of 0.5 lpm, passage 416 b corresponds to a flow rate of 1.0 lpm, passage 416 c corresponds to a flow rate of 2.0 lpm, passage 416 d corresponds to a flow rate of 3.0 lpm, and passage 416 e corresponds to a flow rate of 4.0 lpm.

In one embodiment, flow restrictor 404 includes orifices sized to correspond to the flow rate of the respective passage 416 (similar to flow restrictor 204). Referring to FIG. 5B, in the illustrated embodiment, each passage 416 of flow restrictor 404 includes a first portion 442 and a second portion 444. First portion 442 permits the flow of fluid when aligned with fluid inlet 104 and fluid outlet 106 to pass from a first side 441 of flow restrictor 404 to a second side 443 of flow restrictor 404.

Second portion 444 intersects with first portion 442 and is shown perpendicular to first portion 442. In other examples, second portion 444 forms an acute angle with first portion 442. Second portion 444 is sized to receive an occluder or flow calibrator 446. Occluder 446 is configured to at least partially intersect with first portion 442 and to reduce a cross-sectional area of first portion 442. By reducing the cross-sectional area of first portion 442, occluder or flow calibrator 446 controls the corresponding flow rate of respective passage 416 for fluid flowing from first side 441 to second side 443.

In the illustrated embodiment, occluder 446 is a spherical occluder or ball 448. Ball 448 is press fit into second portion 444 with a tool (not shown). The tool advances ball 448 into second portion 444 and ultimately into first portion 442 to a position wherein the resultant cross-sectional area of first portion 442 corresponds to the desired flow rate for the respective passage 416. It should be noted that passage 416 includes a recess 449 configured to receive a portion of ball 448 when ball 448 is further advanced by the tool. Ball 448 and second portion 444 generally form a tight seal so that fluid does not pass by ball 448 and through second portion 444. Other types of occluders may be used, such as needle valves inserted in second portion 444.

In one exemplary method, flow restrictor 404 is positioned in a fixture (not shown) and aligned with a fluid inlet and a fluid outlet such that a flow of fluid is passing through passage 416. The flow rate of passage 416 being monitored by a detector as is well know in the art. The tool then slowly advances ball 448 in second portion 444 until the monitored flow rate drops to the corresponding desired or calibrated flow rate for passage 416 indicating that the correct cross-sectional area of first portion 442 has been achieved.

In one embodiment ball 448 is inserted from one of sides 441, 443 of flow restrictor 404 to at least partially occlude the flow of passage 416. U.S. Pat. No. 4,366,947 to Voege (“Voege”) and U.S. Provisional Patent Application Ser. No. 60/620,890, filed Oct. 21, 2004, titled “A FLUID REGULATOR”, (“'890 Application”), both provide at least one exemplary embodiment of occluding flow by the insertion of a ball type occluder into a passage from an axial face of a flow restrictor. Both Voege and the '890 Application are expressly incorporated by reference herein. It should be noted that the occlusion methods shown in both Voege and in the '890 Application introduces a bend into the fluid flow path through flow restrictor 404 such that flow passage 416 is non-linear.

Referring to FIG. 5A, flow restrictor 404 includes a plurality of indexes or recesses 450 which cooperate with a detent, such as ball 554 in FIG. 19. Indexes 450 are positioned such that each one corresponds to the alignment of a respective fluid passage 416 with fluid inlet passage 104 and fluid outlet passage 106. In another embodiment, indexes 450 are bumps which cooperate with depressions on body 102.

Referring to FIG. 5D, a diagrammatic representation of a modified flow restrictor 404′ is shown. Flow restrictor 404′ is generally the same as flow restrictor 404 except that first portion 442′ of flow restrictor 404′ includes a first section 442 a′ and a second section 442 b′ offset from first section 442 a′. In flow restrictor 404, first portion 442 is generally positioned along a single axis, not along two axes. In flow restrictor 404′, first section 442 a′ and second section 442 b′ are positioned along two separate axes 443 a, 443 b, respectively. During normal operation, one of fluid passage 104 (see FIG. 1) or 547 and fluid passage 106 (see FIG. 1) or 590 is in fluid communication with section 442 a′ and the other of fluid passage 104 or 547 and fluid passage 106 or 590 is in fluid communication with section 442 b′ during normal operation. However, as shown in FIG. 5D axis 443 a of fluid section 442 a′ is not aligned with an axis 447 of fluid passage 547 and axis 443 b of fluid section 442 b′ is not aligned with axis 449 of fluid passage 590. In the illustrated embodiment, axis 447 and axis 449 are aligned.

The relationship of first section 442 a′, second section 442 b′, fluid passage 547, and fluid passage 590 is such that one of the first section 442 a′ and second section 442 b′ is shut off from its respective fluid passage of fluid passages 547, 590 prior to the other of first section 442 a′ and second section 442 b′ during the rotation of flow restrictor 404′. A first side 445 a of fluid section 442 a′ is generally positioned proximate a first side 451 of fluid passage 547 while a second side 445 b of fluid section 442 a′ is generally positioned further offset from second side 453 of fluid passage 547 than first side 445 a is from first side 451. A first side 455 a of fluid section 442 b′ is generally positioned proximate a first side 457 of fluid passage 590 while a second side 455 b of fluid section 442 b′ is generally positioned further offset from a second side 459 of fluid passage 590 than first side 455 a is from first side 457.

Referring to FIG. 5D, a clockwise rotation of flow restrictor 404′, generally denoted by direction 461, results in fluid section 442 b′ being shut off from fluid passage 590 prior to fluid section 442 a′ being shut off from fluid passage 547. A counterclockwise rotation of flow restrictor 404′, generally denoted by direction 463, results in fluid section 442 a′ being shut off from fluid passage 547 prior to fluid section 442 b′ being shut off from fluid passage 590.

When axle 220′ is used with flow selector 400 or 400′ a second fluid inlet passage 548 (shown in FIG. 14) may be coupled to a first end 223 of axle 220′ and a second fluid outlet passage 618 (shown in FIG. 14) may be coupled to a second end 225 of 220′ to provide a second flow of fluid through central passage 221. As such, the combination of flow selector 400 or 400′ and axle 220′ permits a metered or calibrated flow of fluid through flow selector 400 or 400′ and a second flow of fluid through central passage 221 of axle 220′. Example uses for the second flow of fluid include providing a continuous flow line to the patient, such as for a fluid conserver application device, and/or to provide a fluid supply for the operation of an application device, such as providing pressure to one side of a diaphragm of a pneumatic fluid conserver application device.

Referring to FIG. 6A, a flow regulator 300 including a body 301 and flow selector 200 is shown. It should be understood that one of flow selector 200′; 400, 400′ can be used in place of flow selector 200. Flow selector 200 is rotatably coupled to a first portion 302 of body 301. Illustratively, flow selector 200 is coupled to body portion 302 through axle 220 and the internal components of flow regulator 300, such as a pressure reduction section 170. A second portion 304 of body 301 is coupled to the first portion 302 of body 301. In one example, a second portion 304 includes an application device 306. In another example, as shown in FIG. 6B a second portion 308 of body 301 includes an oxygen conserver application device 310. In the illustrated embodiment, first portion 302 is coupled to a first end 217 of axle 220 and respective second portion 304, 308 is coupled to a second end 219 of axle 220. In another embodiment axle 220 is coupled to only one of first portion 302 and respective second portion 304, 308.

It should be noted that FIGS. 6A-6C are provided to better illustrate the operation of flow regulator 300 and that FIGS. 6A-6C are not intended to be a single cross-section through flow regulator 300 but rather to illustrate various features of the various components of flow regulator 300.

As shown generally in FIGS. 6A, 6B, flow selector 200 is generally positioned within body 302 with a portion of knob 202 being raised above an outer surface 340 of body 302. As such, knob 202 is able to be gripped by a user to adjust the combination of passages 214, 216 which are in communication with fluid inlet 332. However, flow selector 200 does not appreciably enlarge the envelope of flow regulator 300. As such, in one example flow selector 200 is rotatable about an axis offset from the central axis of body 302 but is still substantially within the envelope of flow regulator 300. In another example, flow selector 200 is rotatable about an axis offset from the central axis of body 302 and is completely within or just touching the envelope of flow regulator 300. It should be understood that one of flow selector 200′; 400, 400′ can be used in place of flow selector 200.

Referring to FIG. 9, using an axis 339 of nipple 338 as a reference, an axis 341 intersecting with fluid inlet passage 332 and axle 220 is generally 67° from axis 339. Such orientation is preferred. In another embodiment, axis 341 is generally at another angle from axis 339. Flow selector 400 is illustrated in FIG. 9. However, it should be understood that one of flow selectors 200, 200′, 400′ can be used in place of flow selector 400.

Returning to FIG. 6A, body 302 illustratively includes a yoke 320 configured to couple a source of pressurized fluid 322 to flow regulator 300. In an exemplary embodiment, yoke 320 includes an opening 324 sized to receive a post valve (not shown) and a threaded aperture 326 sized to threadably receive a retainer (not shown). As is known in the art, the retainer urges a fluid outlet of the post valve into engagement with a fluid inlet 328 of flow regulator 300 such that fluid is communicated to flow regulator 300 from the source of pressurized fluid.

Fluid from the source of pressurized fluid 322 enters fluid inlet 328 and is communicated to pressure reduction section 170 which is configured to provide a lower pressure, such as about 5 psi, about 15 psi, about 20 psi, about 22 psi, about 27 psi, about 50 psi, about 60 psi, and the range of about 5 psi to about 60 psi, to a fluid inlet passage 332. This lower pressure is established as a fixed reduced pressure by the particular configuration of the components of pressure reduction section 170 selected for the desired lower pressure output. Fluid in fluid inlet passage 332 is communicated to one of the combination passages 214, 216 through flow selector 200 to provide a metered or calibrated fluid flow to a fluid outlet passage (not shown). Fluid from fluid inlet passage 328 is also provided to a fluid pressure gauge 334 to provide a reading of the pressure in the source of pressurized fluid 322.

Fluid inlet 328 includes a fluid conduit 350 through a fluid inlet retainer 360. Referring to FIG. 6C, fluid inlet retainer 360 includes at least one filter 362, a filter retainer 364, and a seal ring 366. Filter retainer 364 is threadably received within a central opening in body portion 302. Filter retainer 364 includes fluid conduit 350 which has an enlarged portion 368 for receiving one or more filters 362. Filters 362 remove impurities from the fluid, such as from oxygen. In one example, filters 362 are designed to filter particles which are about 0.66 microns or larger.

In one embodiment, two filters are positioned within enlarged portion 368. In another embodiment, three filters are positioned within enlarged portion 368. Exemplary filters include sintered bronze filters having a length of about 0.188 inches and a diameter of about 0.130 inches or filters made from other materials which will not ignite in the presence of oxygen flowing there through at relatively high pressures, such as about 500 to about 3000 psi. In one example filter retainer 364 is made from brass. In alternative embodiment, filter retainer 364 is made from other materials which will not ignite in the presence of oxygen flowing there through at relatively high pressures.

Seal ring 366 includes a seal 370 and a support 372. In one example, seal 370 is made of a flouroelastomer, Viton®, having a durometer of about 75 and support 372 is made of brass. Seal 370 is received within a central opening in support 372 and axially extends outward beyond the axial surfaces of support 372. Seal ring 366 is positioned over filter retainer 364 such that a first portion 376 of seal 370 contacts one of body 302 or filter inlet retainer 364 and such that a top portion 378 of filter inlet retainer 364 extends axially beyond a second portion 380 of seal 370.

First portion 376 of seal 370 provides a seal between one of body 302 and filter retainer 364 and support 372 when the source of pressurized fluid is coupled to flow regulator 300. Second portion 380 of seal 370 provides a seal between support 372 and the source of pressurized fluid when the source of pressurized fluid is coupled to flow regulator 300. As such, when the source of pressurized fluid is coupled to flow regulator 300, seal ring 366 prevents or at least minimizes the passage of fluid from the source of pressurized fluid to anywhere (such as atmosphere) other than fluid conduit 350 of fluid inlet retainer 360.

Fluid conduit 350 is generally shown as a central longitudinal conduit and includes a fluid outlet 384 (see FIG. 6A). The diameter of fluid outlet 384 is generally reduced relative to the diameter of enlarged portion 368 which receives filter 362. In one example, a diameter of fluid outlet 384 is about 0.029 inches. Fluid which passes through filters 362 passes through fluid outlet 384 and is presented to pressure reduction section 170.

Referring to FIG. 6C, fluid inlet retainer 360 further includes at least one radial fluid conduit 386 which is in fluid communication with fluid conduit 350. When fluid inlet retainer 360 is coupled to body portion 102 radial fluid conduit 386 is in fluid communication with a radial passageway 357 in body portion 302. Passageway 357 is in fluid communication with a recess in body portion 302 which is designed to threadably receive pressure gauge 334. Referring to FIG. 6A, pressure gauge 334 includes a face 333 visible through a window 343 which includes indicia to provide an operator with an indication of the pressure of the fluid in the source of pressurized fluid. In one example, the window is made of Lexan. Gauge 334 includes a protective outer member. In one example, the protective outer member is made of rubber.

Returning to FIG. 6C, fluid from radial fluid conduit 384 is prevented from passing to atmosphere adjacent fluid inlet 328 due to seal 370 of seal ring 366 and is prevented from entering cavity 303 in body portion 302 due to seal 396 received by a groove on filter retainer 364 and positioned between filter retainer 364 and the channel in body portion 302 which receives filter retainer 364.

Referring to FIGS. 6A, 7 and 8, pressure reduction section 170 is shown. Pressure reduction section 170 includes a vent mechanism 172, a biasing member 174, a piston 176, and a housing 178. Pressure reduction section 170 is configured to receive a high pressure of fluid, such as greater than 500 psi, and to provide a lower pressure, such as about 5 psi, about 15 psi, about 20 psi, about 22 psi, about 27 psi, about 50 psi, about 60 psi, and the range of about 5 psi to about 60 psi, to one or more fluid inlet passages. This lower pressure is established as a fixed reduced pressure by the particular configuration of the components of pressure reduction section 170 selected for the desired lower pressure output. In one embodiment, housing 178 is coupled to an axle, such as axle 220′, to support a flow selector/flow restrictor, such as flow selector 400, the axle either being solid or containing a fluid conduit which is in fluid communication with the interior of the housing.

As shown in FIG. 8, when assembled biasing member 174 is positioned between vent mechanism 172 and piston 176. Vent mechanism 172, biasing member 174, and piston 176 are each generally received within a cavity 180 (see FIGS. 6C and 7) of housing 178. When assembled, vent mechanism 172 is positioned adjacent fluid outlet 384 of fluid inlet retainer 360. A seal 382 (see FIG. 6C) is positioned between a first surface 385 (see FIG. 6C) of vent mechanism 172 and an axial surface 387 (see FIG. 6C) of body portion 302. Seal 382 is retained in a groove in body portion 302. In a preferred example, the groove is a half dove-tailed groove (see FIG. 6C). Referring to FIG. 7, piston 176 includes a seat surface 184 for receiving biasing member 174. Seat surface 184 is offset from axial surface 186 and is bounded by radial surface 188 thereby forming a recess 190. Recess 190 assists in the retention of biasing member 174 and reduces the overall length of the combination of vent mechanism 172, biasing member 174, and piston 176 (resulting in a reduction of the length of pressure reduction section 170 and hence of flow regulator 300). In one embodiment, the depth of recess 190 from axial surface 186 is about 74% of the distance from axial surface 186 to back surface 196 (see FIG. 8) of piston 176. In one example, the depth of recess 190 is about 0.125 inches and the separation between axial surface 186 and back surface 196 is about 0.169 inches. In one embodiment, piston 176 is made of brass.

Referring to FIGS. 21A and 21B first body portion 512 of conserver portion 504 is shown. Referring to FIG. 21A, a lower surface 580 of first body portion 512 is shown. Lower surface 580 mates with an upper surface 582 (see FIG. 20) of body portion 510. First body portion 512 includes a plurality of openings 584 each sized to receive respective couplers 518 which are then threadably received in openings 519 of body portion 510.

Referring to FIG. 6C, piston 176 includes a stem 191 which includes a central fluid conduit 192 and a transverse fluid conduit 194. As explained in more detail below, fluid enters piston 176 through transverse fluid conduit 194, flows through fluid conduit 192, and exits piston 176 proximate to back surface 196 of piston 176. Stem 191 is received in a central passageway 266 (see FIG. 7) in vent mechanism 172. The height of vent mechanism 172 is chosen such that passageway 266 serves as a guide for piston 176 and to permit the proper travel of piston 176 in directions 268 and 270 shown in FIG. 6C. To this end recess 190 receives an end 272 of vent mechanism 172 as piston 176 travels in direction 270. Therefore, the inclusion of recess 190 in piston 176 permits the length of vent mechanism 172 to be longer and provide a more stable guide for piston 176, while maintaining the overall reduced length of regulator 300 as discussed above. In one embodiment, end 272 moves completely into recess 190 to contact bottom surface 184 of recess 190.

Piston 176 includes a radial groove 181 which receives a seal 198. Seal 198 provides a seal between piston 176 and housing 178 such that fluid is prevented from reaching back surface 196 of piston 176 except through fluid conduit 192. A recess 260 is formed in the end of stem 191 to receive a seal 263 (see FIG. 7). Seal 263 is positioned such that it can contact a seat surface 197 (see FIG. 6C) of fluid inlet retainer 130. In one example, seal 262 is a made of a glass filled Teflon, such as 15% glass filled Teflon. Piston 176 further includes a recess 267 to receive a seal 265. Seal 265 seals between piston 176 and base 172.

Pressure reduction section 170 is held in place relative to body portion 102 by a retainer 271. Retainer 271 is shown as a clip that is received in a groove of cavity 303 of body 302. In an alternative embodiment, pressure reduction section 170 is threadably received in cavity 303, is press fit into cavity 303, or secured by other suitable methods.

The operation of pressure reduction section 170 is described with reference to FIG. 6C. In the absence of any fluid flow biasing member 174 of pressure reduction section 170 biases piston 176 in direction 268 relative to vent mechanism or base 172 such that back surface 196 of piston 176 is positioned adjacent a seat surface 177 in housing 178 and such that vent mechanism 172 is in contact with seal 382. Flow regulator 300 is coupled to a source of pressurized fluid 322 such that high pressure fluid enters fluid inlet retainer 360 from source of pressurized fluid 322. The fluid then passes through filters 362, and exits fluid inlet retainer 360 through fluid outlet 384. This fluid passes through transverse conduit 194 of piston 176 and down central conduit 192 of piston 176. The fluid, assuming it is at a high enough pressure, builds up on the back side of piston 176 (adjacent back surface 196) causing piston 176 to move generally in direction 270. If flow selector 200 is set such that fluid is not permitted to pass through flow selector 200 (none of fluid passages 216 are aligned with fluid outlet 332 in housing 178), then piston 176 continues to move in direction 210 against the bias of biasing member 174 due to the pressure buildup on the backside of piston 176. As piston 176 moves in direction 270, seal 262 of piston 176 moves closer to seat surface 197 of fluid inlet retainer 130. Assuming pressure continues to build (flow selector 200 is not moved to permit fluid to exit through fluid outlet 332) seal 262 contacts seat surface 197 and fluid flow is prevented from exiting fluid inlet retainer 360.

As flow selector 200 is moved to a flow setting, fluid is permitted to flow through fluid conduit 332 in housing 178, through the corresponding fluid conduit 214 of flow selector 200, and to application device 310. Flow selector 200 is moved to a flow setting by a user imparting a rotation to flow selector 200. As stated above, a detent cooperates with indexes 250 to provide an indication to the user of when a fluid channel 216 is aligned with fluid outlet 332.

As fluid flows through flow selector 200, the pressure on the backside of piston 176 is reduced and piston 176 moves in direction 268 due to biasing member 174 such that seal 262 of piston 176 is spaced apart from seat surface 197. This movement once again permits fluid to exit fluid retainer 360 and to flow through piston 176. As time goes on and as long as the flow selector 200 is moved to a flow setting, a cyclic pattern is established wherein the pressure on the backside of piston 176 builds resulting in piston moving in direction 270 and thereby reducing the amount of fluid which flows to the backside of piston 176 followed by the pressure on the backside of piston 176 decreasing resulting in piston 176 moving in direction 268 and thereby increasing the amount of fluid which flows to the backside of piston 176.

Vent mechanism 172 also provides a safety feature to prevent a buildup of pressure in the interior of housing 178. Vent mechanism 172 includes a recess 173 (see FIG. 7) which is in fluid communication with fluid outlet 384. As pressure builds up in recess 173 (potentially due to an obstruction of the fluid passage 192 in piston 176), vent mechanism 172 can move in direction 268 against the bias of biasing member 174. Such movement brings recess 173 into fluid communication with region 180 in housing 178. As shown in FIG. 7, housing 178 includes a vent opening 183 in wall 185. Vent opening 183 is aligned with corresponding vent openings (not shown) in body 302 and cooperate with the vent openings in body 302 to bring region 180 in fluid communication with the air surrounding flow regulator 300. As such, an excessive pressure buildup may be vented to atmosphere. In one embodiment housing 178 and body 302 each include two vent openings.

Housing 185 further includes a recess 269 sized to receive a seal 259. Seal 259 seals between housing 185 and the interior cavity of body 302.

Referring to FIG. 6A, a second fluid passage 335 receiving fluid from pressure reduction section 170 may be included in flow regulator 300 to provide a second flow of fluid. Example uses for the second flow of fluid include providing a continuous flow line to the patient for a fluid conserver application device or a fluid supply for providing pressure to one side of a diaphragm of a pneumatic fluid conserver application device. As shown in FIG. 6A, passage 335 is located below flow selector 200. In another embodiment, in FIG. 6B, instead of second fluid passage 335 passing below flow selector 200, flow selector 200 uses axle 220′ such that the second flow of fluid passes through the channel 221 of axle 220′ and hence through flow selector 200 without passing through one of passages 216.

Referring to FIG. 10, an exemplary fluid conserver device 500 is shown. Conserver 500 includes a flow regulator portion 502 and a conserver portion 504. Flow regulator 502 is generally similar to flow regulator portion 300. Conserver portion 504 is configured for use with a single lumen cannula 503 (see FIG. 13). However, as explained herein, conserver portion 504 may also be configured for use with a dual lumen cannula (not shown).

Conserver 500 is configured to provide at least one metered or calibrated flow of fluid to the single lumen cannula in a continuous mode of operation and/or an intermittent mode of operation. In the continuous mode of operation, conserver 500 provides a continuous flow of fluid to a patient through the single lumen cannula. In the intermittent mode of operation, conserver 500 provides pulses of fluid to a patient through the single lumen cannula. As explained herein conserver 500 can also be configured for use with a dual lumen cannula and be configured to provide at least one metered or calibrated flow of fluid to the dual lumen cannula in a continuous mode of operation and/or an intermittent mode of operation. Both configurations of conserver 500 (single lumen and dual lumen) preferably are capable of providing one or more metered or calibrated flows to the respective cannula in a continuous mode of operation and/or intermittent mode of operation.

In one embodiment, the timing of the pulses and/or the duration of the pulses are triggered by the breathing cycle of the patient. In another embodiment, the timing of the pulses and/or the duration of the pulses are controlled by a pneumatic controller which uses the pneumatic characteristics of conserver 500 to move a valve or piston. In still a further embodiment, the timing of the pulses and/or the duration of the pulses are controlled by an electronic controller which activates an electrically or pneumatically activated valve or piston. The electronic controller is either integrated with the application device or separate from the application device. In still another embodiment the timing of the pulses and the duration of the pulses are controlled by a combination of one or more of the patient's breathing cycle, a pneumatic controller, and an electrical controller.

Flow regulator 502 is generally similar to flow regulator 300 described herein. It should be understood that the discussion above related to flow regulator 300 is generally applicable to flow regulator 502.

Referring to FIG. 16, flow regulator 502 includes a main body 510 having an internal cavity 511 sized to receive pressure reduction section 170 and a flow selector 400 (see FIG. 19). Pressure reduction section 170 receives fluid from a fluid inlet retainer 531 (see FIG. 13) and is configured to provide a lower pressure, such as about 5 psi, about 15 psi, about 20 psi, about 22 psi, about 27 psi, about 50 psi, about 60 psi, and the range of about 5 psi to about 60 psi, to a fluid inlet passage 332. This lower pressure is established as a fixed reduced pressure by the particular configuration of the components of pressure reduction section 170 selected for the desired lower pressure output. Fluid inlet retainer 531 is generally similar to fluid inlet retainer 360.

Returning to FIG. 10, conserver portion 504 includes a first body portion 512, a second body portion 514 and a third body portion 516. Body portion 510 of flow regulator portion 502 and body portions 512, 514, 516 of conserver portion 504 are assembled, such as by stacking, to provide conserver 500. As explained in more detail below, couplers 518 (see FIG. 12) are received in corresponding openings in body portions 512, 514, 516 of conserver 504 and are threaded into openings 519 (see FIG. 16) of body portion 510 of flow regulator 502. In the illustrated embodiment, body portions 510, 512, 514, 516 are configured such that there is only a single orientation that corresponds to a proper assembly of body portions 510, 512, 514, 516.

In an illustrated embodiment, the single orientation is defined by the spacing of the respective openings in 510, 512, 514, 516 which receive couplers 518. Referring to FIG. 16, the respective openings whose location corresponds to the locations of couplers 518 are spaced around the body portions 510, 512, 514, 516 such that only a single orientation of body portions 510, 512, 514, 516 will result in allowing couplers 518 to pass through the respective openings and to couple the respective body portions 510, 512, 514, 516 together. In an alternative embodiment, the various body portions include key features and respective key recesses to orient the respective body portions relative to each other. In another alternative embodiment the various body portions include mounting components which couple the respective body portions together. The assembly of conserver 500 is explained in more detail with respect to FIGS. 16-29.

Referring to FIG. 13, body 510 includes a yoke 520 configured to couple a source of pressurized fluid 522 to conserver 500. Yoke 520 includes an opening 524 sized to receive a post valve and a threaded aperture 526 sized to threadably receive a retainer 527. As is known in the art, retainer 527 urges a fluid outlet of the post valve into engagement with a fluid inlet 528 of flow regulator 502 such that fluid is communicated to flow regulator 502 from the source of pressurized fluid 522. Fluid from fluid passage 528 is provided to a fluid pressure gauge 529 through fluid passage 533 to provide a reading of the pressure in the source of pressurized fluid 522.

Referring to FIGS. 17A-D, body 510 includes several regions for the inclusion and/or placement of instructions or other indicia 541. In the illustrated embodiment, company identification information is located in region 543, instructional or informational text is located in regions 545 a-d. Further, indicia 541 may include alignment indicia in regions 551 a-c to assist in communicating to a user the selected flow rate of flow selector 400 and/or the mode of operation of conserver 500.

Referring to FIG. 7 and 16, pressure reduction section 170 includes a vent mechanism 172, a biasing member 174, a piston 176, and a housing 178. Pressure reduction section 170 is configured to provide a lower pressure, such as about 5 psi, about 15 psi, about 20 psi, about 22 psi, about 27 psi, about 50 psi, about 60 psi, and the range of about 5 psi to about 60 psi, to one or more fluid inlet passages. This lower pressure is established as a fixed reduced pressure by the particular configuration of the components of pressure reduction section 170 selected for the desired lower pressure output.

As illustrated in FIG. 8, biasing member 174 is positioned between vent mechanism 172 and piston 176. Vent mechanism 172, biasing member 174, and piston 176 are each generally received within a cavity 180 (see FIG. 7) of housing 178. When assembled, vent mechanism 172 is positioned adjacent seal 542 (see FIG. 14) and pressure reduction section 170 is held in place by a retainer 544 (see FIG. 16). Retainer 544 is shown as a clip that is received in a groove of cavity 511 of body 510. In an alternative embodiment, flow reduction member 530 is threadably received in cavity 511, is press fit into cavity 511, or secured by other suitable methods.

As explained in more detail below with reference to FIG. 14, pressure reduction section 170 includes a first fluid passage 546 through an opening in piston 176 a second fluid passage 548 formed in the space between piston 176 and an interior surface 550 of housing 178 and a third fluid passage 547 generally aligned with first fluid passage 546. Fluid from fluid passage 547 is communicated to one of the fluid passages 416 through flow selector 400 to provide a metered or calibrated fluid flow to a fluid outlet passage as discussed in more detail below.

Referring to FIG. 16, housing 178 is coupled to an axle, such as axle 220′. Axle 220′ is press fit into an opening of housing 178. In alternative embodiments, axle 220′ is threadably received by an opening in housing 178, secured to housing 178 with an adhesive or by a mechanical joint, such as a weld, is integrally formed with housing 178, or is rotatably coupled to housing 178. As explained above, axle 220′ has a fluid passage 221 formed therein. Fluid passage 221 in one embodiment is a calibrated fluid passage such that a known fluid flow rate is associated with fluid passage 221. In alternative embodiments, a solid axle is used.

Referring to FIG. 14, fluid passage 221 is in fluid communication with fluid passage 548 of pressure reduction section 170. As explained in more detail below, in one embodiment, fluid passing through fluid passage 548 and fluid passage 221 is used to control the operation of a demand piston 734.

Referring to FIGS. 14, 19, and 20, flow selector 400 is rotatably coupled to axle 220. A central channel 452 (see FIG. 19) of flow selector 400 receives axle 220′. In an alternative embodiment, axle 220′ is fixably coupled to flow selector 400 and is rotatably coupled to pressure reduction section 170.

As discussed above, flow selector 400 includes a plurality of recesses 450 sized to receive a detent 554 (see FIG. 19). Recesses 450 cooperate with detent 554 to align respective flow passages 416 in flow selector 400 with flow passage 547 in pressure reduction section 170 and to provide a positive indication to the user of such alignment. Referring to FIG. 19, detent 554 is a spherical ball which is at least partially received in a recess 556 of housing 178 of pressure reduction section 170. Detent 554 is sized to cooperate with recesses 450 in flow selection 400.

A biasing member 558, illustratively a spring, is also received in recess 556 of housing 178 and biases detent 554 into recess 450 of flow selector 400. Additional exemplary detents include a bump on the surface of housing 178 or a plastic insert having a bump. In alternative embodiments, detent 554 is received in a recess of flow selector 400 and housing 178 includes a plurality of recesses each one corresponding to the alignment of a fluid passage 416 in flow selector 400 with fluid passage 547 in pressure reduction section 170.

Once detent 554 and biasing member 558 are positioned in recess 556, flow selector 400 is positioned over axle 220′ such that one of recesses 450 of flow selector 400 is cooperating with detent 554 and such that a back surface 441 (see FIG. 5B) of flow selector 400 is in contact with seal 560 (see FIG. 19) which prevents or minimizes the escape of fluid as the fluid passes from fluid passage 547 in pressure reduction section 170 into fluid passage 416 of flow selector 400. In the illustrated embodiment of FIG. 14, seal 560 and two additional seals 561, 563 assist to prevent or minimize the escape of fluid as fluid passes from fluid passage 547 in pressure reduction section 170 into fluid passage 416. Seals 560, 561, and 563 cooperate to act as a silencer or muffler as flow sector 400 is rotated during the selection of the appropriate fluid passages 416.

Referring to FIG. 19, flow selector 400 is axially held in place by a retainer 564 such that back surface 441 (see FIG. 5B) of flow selector 400 remains in contact with seal 560 and such that one of recesses 450 is cooperating with detent 554. Retainer 564 is received in a circumferential channel in axle 220′. A seal 562 is positioned over retainer 564. In an alternative embodiment, flow selector 400 is held in place by conserver 504, a nut threadably received by axle 220′ or other suitable securing means that axially secure flow selector 400 while still permitting flow selector 400 to be rotatable relative to axle 220′.

Flow selector 400 is shown assembled with body 510 and pressure reduction section 170 in FIG. 20. It should be noted that radial surface 422 is accessible from the exterior of body portion 510 and that a user can input a rotation to flow selector 400.

Referring to FIGS. 21A and 21B first body portion 512 of conserver portion 504 is shown. Referring to FIG. 21A, a lower surface 580 of first body portion 512 is shown. Lower surface 580 mates with an upper surface 582 (see FIG. 20) of body portion 510. First body portion 512 includes a plurality of openings 584 each sized to receive respective couplers 518 which are then threadably received in openings 586 of body portion 510.

First body portion 512 includes a central fluid passage 588 configured to align with the respective one of fluid passages 416 in flow selector 400 which is currently aligned with fluid passage 547 in flow regulator portion 502. As best shown in FIG. 14, central fluid passage 588 includes a first portion 590 sized to receive seals 592, 594, a second portion 596, and a third portion 598 sized to receive seal 600. Seals 592, 594 seal the transition from fluid passage 416 in flow selector 400 to fluid passage 588 in first body portion 512. As explained in more detail below, seal 600 seals the transition from fluid passage 588 and a fluid passage 602 in first body portion 512 and provides a seat for demand piston 734.

Referring to FIG. 14, fluid passage 602 includes a first portion 604 which intersects with third portion 598 of fluid passage 588 and a second portion 606 sized to be threadably coupled to a nipple 608. Nipple 608 is configured to couple to single lumen cannula 503 (see FIG. 13) as is well known in the art. A seal (not shown) is provided to seal the connection between fluid passage 602 and nipple 608.

It should be noted that FIGS. 13, 14, and 14A-D are provided to better illustrate the operation of conserver 500 and that FIGS. 13, 14, and 14A-D are not intended to be a single cross-section through conserver 500 but rather to illustrate various features of the various components of conserver 500.

First body portion 512 further includes fluid passage 616 having a first portion 618 sized to receive axle 220′, a second portion 620, and a third portion 622. First portion 618 is sized to receive an end of axle 220′ and is in fluid communication with channel 221 of axle 220′. Further, first portion 618 includes a recess sized to receive seal 562 which seals the connection between axle 220′ and first body portion 512. Third portion 622 is sized to receive a seal 612 which is sized to seal the connection between fluid passage 616 and first mode selector member 670.

As explained herein, the flow characteristics of fluid passage 616 are adjustable with a needle valve 642 (see FIG. 21A and 12D). As illustrated in FIG. 14 the three portions 618, 620, 622 of fluid passage 616 are arranged in a linear relationship. In a preferred embodiment shown in FIGS. 12A and 12D, portions 618 and 622 are longitudinal passages formed part way through first body portion 512 and are not aligned. Portions 618 and 622 are connected by transverse portion 620 which is explained herein interacts with needle valve 642.

Referring to FIGS. 12 and 12D, first body portion 512 further includes a opening 640 sized to receive a needle valve 642. As shown in FIG. 12D, opening 640 intersects with fluid passage 616 such that a tip 644 of needle valve 642 is positionable within a portion of passage 616. Needle valve 642 is threadably received by opening 640 and includes a tool engagement portion 646 for engagement by a tool. In the illustrated embodiment, tool engagement portion 646 is configured to be engaged by a flat screwdriver which can be used to advance needle valve 642 into and out of opening 640. A seal 648 is positioned on a seat 650 (see FIG. 21A) of needle valve 642 and cooperates with opening 640 to prevent the passage of fluid from the tip side 644 of needle valve 642 to the tool engagement side 646 of needle valve 642.

By adjusting the position of tip 644 within fluid passage 616, the cross-sectional area of second portion 620 of fluid passage 616 may be adjusted. As such, needle valve 642 is used to adjust the rate at which fluid passes from first portion 618 of fluid passage 616 to third portion 622 of fluid passage 616. The cross-sectional area effects the sensitivity of conserver 504 as explained in more detail below.

Returning to FIG. 21A, first body portion 512 further includes an alignment feature 634 configured to mate with an alignment feature of flow selector 400 (such as pin 480 shown in FIG. 20). In the illustrated embodiment, alignment feature 634 is a groove sized to receive pin 480. Pin 480 is received in a recess (not shown) of flow selector 400. Alignment feature 634 has two depths (see FIG. 12B), a first depth to accommodate a ridge 481 of flow selector 400 and a second depth to accommodate pin 480. The portion of alignment feature 634 which is configured to accommodate ridge 481 is generally circular while the portion of alignment feature 634 configured to accommodate pin 480 is generally a sector of a circle. The sector of alignment feature 634 and pin 480 cooperate to limit the rotation of flow selector 400.

Referring to FIG. 23A, first body portion 512 is shown assembled to flow regulator portion 502. As shown in FIG. 21B, first portion 512 includes a first rear axial surface 660 which as explained below is positioned adjacent a surface 778 (see FIG. 25A) of second body portion 514 and a second rear axial surface 664 recessed from first axial surface 660. As explained in more detail below, recess 667 (see FIGS. 21B and 23A) formed by second axial surface 664 and is sized to receive first mode selector member 670 and second mode selector member 672. As explained in more detail herein, first mode selector 670 and second mode selector 672 cooperate to configure conserver portion 504 for use in one of an intermittent mode of operation or a continuous mode of operation.

As shown in FIG. 14, seal 600 is positioned adjacent to fluid passage 588 and seal 612 positioned adjacent to fluid passage 616. Returning to FIG. 23A, a recess 676 which is coaxially aligned with fluid passage 588 is formed or otherwise created in second rear axial surface 664. Recess 676 is sized to receive a portion of demand piston 734 and to provide a seat for seal 600. A seal 682 is also received in recess 676. Seal 682 along with seal 612 seals the connection between first body portion 512 and first selector member 670.

In the illustrated embodiment, two addition recesses 677 are formed in second axial surface 664. Recesses 667 are sized to receive two additional seals similar to seal 612. These two additional seals and seal 612 provide three points of contact with a bottom surface 671 (see FIG. 32) of first selector member 670.

A seal 686 is also shown positioned with a recess 688 of first rear axial surface 660 of first body portion 512. As best shown in FIG. 12C, a fluid passage 690 connects recess 688 with second portion 606 of fluid passage 602. Seal 686 seals the connection between second body portion 514 and first body portion 512 around fluid passage 690. As explained in more detail below, fluid passage 690 is utilized with third body portion 516 configured for use with a single lumen cannula to bring fluid passage 602 and a cavity 775 into fluid communication.

Referring back to FIG. 23A, an alignment member 700 is shown along with a detent 702. Alignment member 700 is received in an elongated arcuate slot 704 of second mode selector 672. The movement of second mode selector 672 in directions 706, 708 (see FIGS. 12A-24) is limited by one of contact between alignment member 700 and an edge of slot 704 or contact between a wall 710 of recess 667 and a side wall 712 of second mode selector 672. The pivoting of second mode selector 672 about alignment member 700 is minimized by the generally concentric arrangement of surface 714 of second mode selector 672 and outer surface 716 of first body portion 512 and/or outer surface 774 of second body portion 514 (see FIG. 12B) and the interaction between first mode selector 670 and second mode selector 672.

Second mode selector member 672 further includes two opening 720, 722 each of which are concentrically aligned with detent 702 relative to passage 588. Openings 720, 722 correspond to two preferred positions of second mode selector 672. As explained in more detail herein, opening 720 corresponds to the selection of a continuous mode of operation of conserver device 500 and opening 722 corresponds to the selection of an intermittent mode of operation of conserver device 500. Second mode selector 672 further includes a textured portion 724 configured to aid the transfer of force from a user's hand to second mode selector 672.

First mode selector 670 includes a recess 730 having a central opening 731. Recess 730 is sized to receive a biasing member 732 and demand piston 734. Biasing member 732 and demand piston 734 are assembled as shown in FIG. 23B and then received by recess 730 as shown in FIG. 24.

Referring to FIG. 23B, demand piston 734 includes a first portion 736 and a second portion 738. Second portion 738 includes a reduced end portion 740 having a seat surface 739 configured to mate with seal 600 as shown in FIG. 14B, in the illustrated embodiment, seat surface 739 is spaced apart from a tip or end 741 of second portion 738. First portion 736 includes a recess sized to receive biasing member 732 which is compressed between a surface 742 (see FIG. 14) of demand piston 734 and a surface 744 (see FIG. 23A) of first mode selector member 670.

Returning to FIG. 14, biasing member 732 generally biases demand piston 734 in direction 750 such that flow passage 588 is in fluid communication with fluid passage 602. However, biasing member 732 is compressible to permit the movement of demand piston 734 in direction 752 such that reduced portion 740 of demand piston 734 is sealed against seal 600. When reduced portion 740 is sealed against seal 600, fluid passage 588 is no longer in fluid communication with fluid passage 602. As such, by controlling the positioning of demand piston 734 relative to seal 600, the passage of fluid from fluid passage 588 to fluid passage 602 and hence to the patient through cannula 503 which is attached to nipple 608 can be controlled.

Referring to FIG. 12D, first mode selector member 670 includes a fluid passage 760. Fluid passage 760, as shown in FIGS. 12D and 14, is positioned to align with fluid passage 616 at least in one orientation of first mode selector member 670. As explained in more detail herein, fluid passage 760 aligns with fluid passage 616 when conserver 504 is configured to operate in an intermittent mode of operation and fluid passage 760 is not aligned with fluid passage 616 when conserver 504 is configured to operate in a continuous mode of operation.

Referring to FIG. 23A, first mode selector member 670 includes a recess 762 (see FIG. 32) which is configured to receive a tab 764 of second mode selector member 672. The reception of tab 674 in recess 762 effectively couples first mode selector member 670 to second mode selector member 672 such that a rotation of second mode selector 672 in one of directions 706, 708 will result in a corresponding rotation of first mode selector 670. Therefore, by moving second mode selector 672, a user is able to cause the rotation of first mode selector 670 and thus select either a continuous mode of operation for conserver 504 or an intermittent mode of operation for conserver 504 (based on the alignment or non-alignment of fluid passage 760 with fluid passage 616). It should be noted that the selection of the mode of operation is independent of the selection of a fluid flow rate with flow selector 400. However, the selection of the mode of operation can be constrained based on the selection of a fluid flow rate with flow selector 400 as explained herein.

Referring to FIGS. 25A and D, second body portion 514 includes a vent fluid passage 770 which connects a front surface 772 of second body portion 514 and a radial surface 774 of second body portion 514. A rear surface 778 of second body portion 514 includes a recess 780 sized to receive first mode selector member 670 and a seal 782 (see FIG. 12B) which seals the connection between second body portion 514 and first mode selector member 670. Further, a surface 784 of recess 780 includes a fluid channel 786 which connects surface 784 to the front side of second body portion 514.

Referring to FIG. 25D, fluid channel 786 intersects the front side of second body portion 514 in a raised portion 788 of second body portion 514. Raised portion 788 includes a seat surface 790 (see FIG. 14) which as explained in more detail below provides a seat for a pad 792 (see FIG. 14) of a diaphragm 794 (see FIG. 14).

Referring to FIG. 28, diaphragm 794 illustratively includes a flexible portion 796 and a support 798. Flexible portion 796 permits the movement of diaphragm 794. Support 798 provides some rigidity to diaphragm 794 in order to provide better control over the movement of diaphragm 794. In one embodiment, support 798 is coupled to flexible portion 796 with adhesive. In another embodiment, the support includes a plurality of apertures which are sized to receive a corresponding plurality of buttons formed on the diaphragm. The buttons each include a lip or ridge that retains the button and thus the diaphragm relative to the support. In a further embodiment, the flexible portion is molded over the support.

An outer portion 804 of diaphragm 794 is fixably held by second body portion 514 and third body portion 516. Outer portion 804 is supported by seat 806 (see FIG. 26) of second body portion 514 and held in place due to both seat 806 of second body portion 514 and a seat 808 (see FIG. 27A) of third body portion 516. While outer portion 804 is held by second body portion 514 and third body portion 516, a central portion 810 of diaphragm 794 is able to move in directions 750, 752 (see FIG. 14) relative to outer portion 804 due to the flexible nature of diaphragm 794.

Referring to FIG. 14, central portion 810 including pad 792 is able to move in directions 750, 752 relative to outer portion 804. Returning to FIG. 56, third body portion 516 includes cavity 775 which permits the movement of diaphragm 794 in direction 750. Referring to FIG. 29, third body portion 516 further includes an aperture 818 which threadably receives an adjuster 820. Referring to FIG. 27A, adjuster 820 includes a tool engagement portion 822 and a tapered portion 824. Tapered portion 824 is configured to receive a first end 826 of a biasing member 828. A second end 830 of biasing member 828 contacts diaphragm 794 generally in central portion 810. As shown, in FIG. 28, in one embodiment, second end 830 of biasing member 828 is received by a bump 832 on diaphragm 794.

Biasing member 828 is used to bias central portion 810 of diaphragm 794 in direction 752 such that pad 792 contacts seat 790 (see FIG. 14). By adjusting how far adjuster 820 is advanced into or out of aperture 818, the amount of force exerted by biasing member 828 on diaphragm 794 may be adjusted. Therefore, the amount of force required to move diaphragm 794 such that pad 792 is spaced apart from seat 790 may be adjusted.

Referring to FIGS. 25D, second body portion 514 further includes a fluid channel 771 which connects a front surface 763 of second body portion 514 with back surface 778 of second body portion 514. Referring to FIG. 12C, fluid channel 771 is aligned with recess 688 in first body portion 512 when second body portion 514 is assembled to first body portion 512. As explained in more detail below, fluid channel 771 is further aligned with a fluid channel 773 (see FIG. 27) in third body portion 516 which is in fluid communication with cavity 775 formed between third body portion 516 and diaphragm 794 through fluid passage 777. As such, fluid passage 606 in first body portion 512 is in fluid communication with cavity 775 through recess 688 (first body portion 512), fluid passage 771 (second body portion 514), fluid passage 773 (third body portion 516 and a corresponding fluid passage in diaphragm 794), and fluid passage 777 (third body portion 516). As explained in more detail below this fluid connection permits the inhalation of the patient and/or the exhalation of the patient to serve as a trigger for the operation of conserver portion 504.

It should be noted that third body portion 516 is for use with the single lumen cannula. Also shown in FIGS. 30A and 30B is a modified third body portion 516′ for use with a dual lumen cannula. Dual lumen third body portion 516′ is generally similar to third body portion 516. However, dual lumen third body portion 516′ does not include fluid passage 773 or fluid passage 777. A second lumen of the dual lumen cannula is instead attached to nipple 779. A fluid passage 783 in nipple 779 is in fluid communication with cavity 775 through fluid passage 781 in third body portion 516′. Fluid passage 781 intersects with aperture 818 below the location of adjuster 820. As such, the inhalation or exhalation of the patient is sensed through the second lumen of the cannula attached to nipple 779 as opposed to through the first lumen and the plurality of fluid passages including fluid passages 773 and 777.

With reference to FIGS. 13, 14, and 14A-D, conserver 500 with the single lumen conserver 502 operates in the following manner. A source of pressurized fluid 522 is coupled to conserver 500 as explained above delivering pressurized fluid ultimately to passages 546, 547, 548 of pressure reduction section 170. Single lumen cannula 503 is coupled to nipple 608. Single lumen cannula 503 is further coupled to a patient. As is well understood in the art, single lumen cannula 503 is configured to provide fluid, such as oxygen, to the patient to aid in breathing.

Fluid from the pressurized source enters fluid passage 528 and passes through fluid passage 546 of pressure reduction section 170. Pressure reduction section 170 provides fluid through fluid passages 547 and 548 at a reduced lower pressure than the pressure of fluid entering pressure reduction section 170 from the source of pressurized fluid 522. As mentioned above fluid passages 547 and 548 communicate fluid to the currently aligned passage 416 of flow selector 400 and passage 221 of axle 220′, respectively.

Conserver portion 504, as shown in FIGS. 14A-C, is operating in the intermittent mode of operation. As such, conserver 504 provides spaced apart pulses of fluid to a patient through cannula 503 which is coupled to nipple 608. The timing of the pulses and the duration of the pulses are controlled by a pneumatic controller comprised generally of demand piston 734. The inputs to the pneumatic controller are discussed below. Conserver portion 504, as shown in FIG. 14D, is operating in a continuous mode of operation wherein a continuous flow of fluid is provided to the patient through cannula 503.

Returning to FIGS. 14A-C, the operation of the pneumatic controller in the intermittent mode of operation is further explained. As discussed herein, the currently aligned passage 416 of flow selector 400 is configured to provide a metered or calibrated restricted flow of fluid, typically in the range of about 0.5 liters per minute to about 5 liters per minute. Fluid exiting passage 416 is passed into passage 588 of first body portion 512. Passage 588 intersects with and is in fluid communication with passage 602 in first body portion 512 unless demand piston 734 blocks the passage of fluid from fluid passage 588 to fluid passage 602. Passage 602 is operably coupled to a nipple 608 which in turn is coupled to single lumen cannula 503 for delivery of fluid to the patient.

FIG. 14A illustrates a startup orientation for conserver portion 504 or the orientation of conserver portion 504 subsequent to the venting of fluid as shown in FIG. 14C. FIG. 14B illustrates the blockage of the flow of fluid from fluid passage 588 to fluid passage 602 by demand piston 734 hence conserving fluid. FIG. 14C illustrates the venting of fluid thereby causing demand piston 734 to be moved such that fluid passes from fluid passage 588 to fluid passage 602.

Returning to FIG. 14A, in the absence of any obstruction, fluid passes from the currently aligned fluid passage 416, to fluid passage 588, to fluid passage 602, and onto the patient through cannula 503. However, reduced portion 740 of demand piston 734 is configured to seal against seal 600 to block the flow of fluid from fluid passage 588 to fluid passage 602 (as shown in FIG. 14B). As explained above, demand piston 734 is biased in direction 750 by biasing member 732 such that reduced portion 740 is spaced apart from seal 600 and fluid passage 588 is in fluid communication with fluid passage 602 (as shown in FIG. 14A). As such, in order to block the flow of fluid from fluid passage 588 to fluid passage 602, demand piston 734 must be moved in direction 752 against the bias of biasing member 732.

The movement of demand position 734 in direction 752 is the result of a build-up of fluid pressure on a back side 735 of demand piston 734 as illustrated in FIG. 14B. Fluid is delivered to back side 735 of demand piston 734 through passage 221 of axle 220′. Passage 221 is in fluid communication with passage 616 of first body portion 512 which in turn is in communication with passage 760 in first mode selector 670. It should be noted that if conserver 504 was operating in a continuous mode of operation as illustrated in FIG. 14D, passage 760 would not be aligned with passage 616 and hence fluid would not be delivered to the back side 735 of demand piston 734. As such, demand piston 734 would be biased in direction 750 by biasing member 732 and fluid passage 602 would be in continuous fluid communication with fluid passage 588.

Returning to the intermittent mode of operation and FIG. 14A, first mode selector 670 and second body portion 514 cooperate to define a cavity 737 proximate to back side 735 of demand piston 734. It should be understood that the pressure of fluid passing through passages 221, 616 and 760 is at a higher pressure than the fluid in passage 588. As such, over time a higher pressure is built up on back side 735 of demand piston 734 and demand piston 734 is moved against the biasing of biasing member 732 in direction 752 resulting in reduced portion 740 sealing against seal 600 such that fluid passage 602 is no longer in fluid communication with fluid passage 588 as illustrated in FIG. 14B.

Reduced portion 740 of demand piston 734 would remain sealed against seal 600 if the higher pressure on back side 735 of demand piston 734 is not relieved. In the illustrated embodiment, the pressure on the back side of 735 is relieved by the permitting of fluid to flow through passage 786 in second body portion 514, through a cavity 787 formed by second body portion 514 and diaphragm 794 and ultimately through vent passage 770 in second body portion 514 to atmosphere as illustrated in FIG. 14C. Once the pressure adjacent back side 735 is relieved, demand piston 734 moves in direction 750 due to the biasing of biasing member 732 resulting in fluid passage 602 again being in fluid communication with fluid passage 588 as illustrated in FIG. 14C.

Central portion 810 of diaphragm 794 is moveable generally in direction 750 from a first position wherein pad 792 is sealed against seat 790 to a second position wherein pad 792 is spaced apart from seat 790 of second body portion 514. When diaphragm 794 is in the first position (see FIGS. 14A and 14B) fluid is prevented or restricted from passing from passage 786 into cavity 787. When diaphragm 794 is in the second position, fluid is permitted to pass from passage 786 into cavity 787 (see FIG. 14C).

Diaphragm 794 is biased in direction 752 (in the first position) by a biasing member 826. As such, diaphragm 794 typically prevents the passage of fluid from passage 786 to cavity 787. However, if the force of biasing member 826 is reduced, then the pressure buildup in fluid passage 786 causes central portion 810 of diaphragm 794 to move in direction 750, thereby permitting fluid to pass from fluid passage 786 into cavity 787 and ultimately to atmosphere.

In one embodiment, the force exerted by biasing member 826 is set such that diaphragm 794 is not moveable in direction 750 solely due to the build-up of pressure on backside 735 of demand piston 734. In this embodiment, conserver 500 requires a trigger to initiate the intermittent flow of fluid to the patient through the single lumen cannula.

In the illustrated embodiment, the trigger is the inhalation of the patient. When the patient inhales, the pressure in cannula 503 is reduced. The reduction in pressure in cannula 503 is communicated to cavity 775 formed by third body portion 516 and diaphragm 794 through the connection of fluid passages 690 (in first body portion 512), 688 (in first body portion 512), 771 (in second body portion 514), 773 (in third body portion 516), and 777 (in third body portion 516) as shown in FIG. 12C. When dual lumen third body portion 516′ is used, the reduction in pressure in the cannula is communicated to cavity 775 through the second lumen attached to nipple 779. The reduction in pressure in cavity 775 aids in the ability to move diaphragm 794 in direction 750 because the reduction in pressure effectively reduces or negates at least a portion of the force exerted by biasing member 826. Further, the combination of the reduction in pressure in cavity 775 and the buildup of pressure on the backside 735 of demand piston 734 overcomes the force of biasing member 826 resulting in diaphragm 794 moving in direction 750 (see FIG. 14C).

Therefore, as the patient inhales central portion 810 of diaphragm 794 is moved in direction 750 against the bias of biasing member 826 due to the buildup of pressure on backside 735 of demand piston 734 and the reduction of pressure in cavity 775 due to the patient inhaling as illustrated in FIG. 14C. Once the seal between pad 792 of diaphragm 794 and seat 790 is lost, the fluid at backside 735 of demand piston 734 is communicated to atmosphere. As the pressure in cavity 737 corresponding to back side 735 decreases, demand piston 734 is moved in direction 750 such that reduced portion 740 is spaced apart from seal 600 and pad 792 of diaphragm 794 returns to seal against seat 790 (see FIG. 14A). The pressure again builds up on backside 735 of demand piston 734 until demand piston 734 is again moved in direction 752 (see FIG. 14B). The further building of pressure in cavity 737 along with the continued reduction in pressure in cavity 775 results in diaphragm 794 and demand piston 734 being once again moved in direction 750 providing a second pulse of fluid (see FIG. 14C). The above cycle is repeated again as long as the pressure in cavity 775 is reduced due to the inhalation of the patient.

Once the patient stops or significantly reduces inhaling and/or is exhaling, the pressure reduction in cavity 775 is lost and/or the pressure in cavity 775 is increased and the force of biasing member 826 is able to completely overpower the force of the pressure buildup on backside 735 in cavity 737. As such, the absence or significant reduction of inhalation and/or the presence of exhalation provides a second trigger to cease the intermittent production of pulses of fluid. The number of pulses of fluid and spacing of the pulses is in part dependent on the breath length and breath depth of the patient.

In one example, the controller inputs or variables discussed herein are set such that two pulses are provided during an exemplary inhalation of a patient. In another example, about 6 to about 10 pulses of fluid are provided during an exemplary inhalation of a patient. In a further example, about 2 to about 10 pulses of fluid are provided during an exemplary inhalation of a patient. In still a further example, about 8 to about 9 pulses of fluid are provided during an exemplary inhalation of a patient.

Referring to FIG. 15, the flow of fluid from passage 588 to passage 602 is represented by curve 970 and an exemplary curve 792 of the pressure in cavity 775 is shown. Curve 792 is generally shaped like a breath curve for a patient due to the fact that cavity 775 is in fluid communication with fluid passage 602 and cannula 503. The overall shape of curve 970 is generally sinusoidal. Illustratively, curve 970 includes seven pulses of fluid 971A-G as shown in FIG. 15. The earlier pulses 971A and 971B generally provide a larger flow rate of fluid due to the pressure buildup in fluid passage 588. The latter pulses 971E-G exhibit a generally constant flow rate of fluid from pulse to pulse. As such, the fluid flow to cannula 503 is somewhat front loaded to the beginning of an inhalation cycle of the patient. Also, as shown in FIG. 15, the spacing between the latter pulses 971 f and 971 g is greater than the spacing between the earlier pulses 971A and 971B due at least in part to the return of the pressure in cavity 775 towards the baseline pressure near the end of the inhalation of the patient.

The amount of fluid communicated to cannula 503 in pulses 971A-G generally corresponds to the metered or calibrated flow of fluid specified by flow setting of conserver 500 assuming that the patient is taking an expected average number of breathes each minute and that each breath has a generally constant length and depth. However, conserver 500 is configured to provide fluid to the patient for every breath and multiple pulses for each breath. As such, a patient which is in a period of activity, such as walking, will likely take more breathes per minute and potentially deeper and/or different length breathes. In such situations, conserver 500 provides a specified amount of fluid to the patient that exceeds the flow setting. Alternatively, if the patient is in a period of inactivity, the patient will likely take fewer breathes per minute and potentially shallower and/or different length breathes. In such situations, conserver 500 provides a specified amount of fluid to the patient that is less than the flow setting. As such, conserver 500 is configured to provide a specified amount of fluid to a patient corresponding to a flow setting for times when the patient is experiencing average breathing characteristics and to adapt to the breathing pattern of the patient for other times, such as activity.

The spacing of the pulses and the widths of the pulses are controlled by varying one or more of the controller inputs discussed herein. In one example, the controller inputs are set such that at least two pulses of fluid are provided for an exemplary inhalation cycle of a patient.

Referring to FIG. 15A, a comparison was performed between conserver 500 as shown herein and embodied as the Flo-Rite™ conserver available from Ameriflo Corporation located at 478 Gradle Drive, Carmel, Ind. 46032, the EasyPulse5 conserving regulator available from Precision Medical located at 300 Held Drive, Northampton, Pa. 18067, and the Cypress OXYPneumatic® conserver, Model 511, available from Chad Therapeutics located at 21622 Plummer Street, Chatsworth, Calif. 91311. Each device was connected to a mechanical simulator to simulate patient breathing. Each device was tested with the simulated breath curve 980 including three breaths 982 a, 982 b, and 982 c. The EasyPulse5 device gave a single pulse of fluid 984 a, 984 b, and 984 c at the beginning of the respective breaths 982 a, 982 b, and 982 c. The Cypress OXYPneumatic® device gave a single pulse of fluid 986 a, 986 b, and 986 c for respective breath 982 a, 982 b, and 982 c. Both the EasyPulse5 device and the Cypress OXYPneumatic® device provided a second pulse at the end of breath 982 c. Such a second single large pulse is very uncomfortable for the patient. In addition the Cypress OXYPneumatic® device gave a large percentage of pulse 986 b outside of the timeframe of the simulated inhale associated with breath 982 b.

In contrast to the EasyPulse5 and Cypress OXYPneumatic® devices, the Flo-Rite™ device provides intended multiple pulses 988 a (five pulses), 988 b (three pulses), and 988 c (eleven pulses) during the inhalation associated with each breath 982 and did not provide pulses 988 outside of the respective inhalation of each breath 982. As such, the patient is not subjected to a large pulse while they are trying to exhale. The overall shape of pulses 988 are generally sinusoidal. The multiple pulses of each pulse set 988, in one embodiment, may be considered a high frequency oscillator output.

Further, the multiple pulses 988 a, 988 b, and 988 c of the Flo-Rite™ device are generally loaded towards the beginning of the inhalation cycle of each breath 982 as exemplified by the larger amplitudes of the initial pulses of each pulse set 988 a, 988 b, and 988 c. Further, the Flo-Rite™ device is able to provide additional fluid for longer breathes, such as breath 982 c, and to provide less fluid for shorter breathes, such as breath 982 b. As such, the Flo-Rite™ device is able to adapt to changes in the fluid needs of the patient, such as when the patient is active.

By giving additional pulses when the patient breath length or depth increases, the Flo-Rite™ device is able to reduce the oxygen saturation recovery times for patients using the Flo-Rite™ device. In one example, the recovery time of a patient with the Flo-Rite™ device was less than about one minute, preferably about one-half of a minute. In another example, the recovery time was about 35 seconds.

Further, the Flo-Rite™ device provides multiple pulses throughout the inhalation cycle of breath 982. The multiple pulses reduces fluid flow reversion and/or reflective losses because the multiple pulses are easier on the body. Also, the multiple pulses reduces the likelihood of lung over-distension and improves patient comfort.

The pneumatic controller of the present invention includes a valve assembly in communication with a fluid passage of the body as discussed above. The pneumatic controller is configured to detect an inhalation of the patient and to provide a series of at least two pulses of the fluid 988 a, 988 b, and 988 c to the output during the inhalation of the patient. The pneumatic controller provides an initial pulse having a fluid amplitude greater than a fluid amplitude of subsequent pulses in the series of at least two pulses without the aid of a fluid reservoir separate from the fluid passage of the body.

The present invention includes a needle control valve 642 in portion 620 of fluid passage 616 which adjusts the flow of fluid from fluid outlet passage 618 to the third portion 622 of fluid passage 616. This permits an oscillation frequency of the sinusoidal fluid pulses to be varied by adjusting the needle valve 642.

In another embodiment, the force on biasing member 826 is set low enough that the pressure build-up on back side 735 of demand piston 734 alone can move diaphragm 794 in direction 750. In this embodiment, conserver 500 is able to provide intermittent pulses of fluid to a patient independent of the breathing force of the patient. Such a configuration may provide extra safety in certain environments, such as pediatric environments or with a patient who is capable of only very shallow breathes which result in minimal pressure reduction in cavity 775.

In still a further embodiment, the force on biasing member 826 is set such that a slight pressure reduction in cavity 775 along with the pressure build-up on back side 735 of demand piston 734 together can move diaphragm 794 in direction 750. As such, conserver 500 still uses a trigger from the breath of the patient, but only requires a minimal amount of pressure reduction for increased safety for certain environments, such as pediatric environments or with a patient who is capable of only very shallow breathes which result in minimal pressure reduction in cavity 775. In one example, the pressure reduction in cavity 775 must be at least about 0.15 cm of water. In another example, the pressure reduction in cavity 775 must be at least about 0.25 cm of water. In yet another example, the pressure reduction in cavity 775 must be at least about 0.35 cm of water.

The pneumatic controller has several inputs or variables each of which has an effect on the timing of the pulses and the duration of the pulses. Primary inputs include the stiffness of biasing member 732, the stiffness of biasing member 826, the stiffness of diaphragm 794, the rate of fluid flow through fluid passages 221 (axle), 616 (first body portion), and 760 (first selector member), the flow rate of fluid through fluid passage 416 (flow selector) and 588 (first body portion), and the size of cavity 737 on the backside of the demand piston.

The values of at least some of these primary inputs are adjustable by a user to calibrate conserver 500, thereby providing variable inputs to the controller. For instance, the effective stiffness of biasing member 826 can be adjusted by further movement of adjuster 820 in one of directions 750 and 752. Further, the flow rate of fluid in fluid passage 616 and hence in fluid passage 760 may be adjusted by adjusting the position of tip 644 of needle control valve 642 in portion 620 of fluid passage 616. Although these inputs may be available to an end user, such as a caregiver, in one embodiment these inputs are not readily available to an end user.

Typically, an end user or caregiver user has two main variable inputs to the pneumatic controller. First, the selection of flow rate to passage 588 by rotating flow selector 400 to select a fluid passage 416 of flow selector 400. By increasing the flow rate by selecting a fluid passage having a higher fluid flow rate, the pneumatic controller will decrease the spacing between pulses (increase the frequency of the pulses) and/or increase the amplitude of each pulse. Conversely, by decreasing the flow rate by selecting a fluid passage having a lower fluid flow rate, the pneumatic controller will increase the spacing between pulses (decrease the frequency of the pulses) and/or decrease the amplitude of each pulse.

Second, the selection of whether to operate in a continuous mode of operation or an intermittent mode of operation by the rotation of second selector member 672. The intermittent mode of operation of conserver 504 is described herein with reference to FIGS. 14A-C and in a dual lumen embodiment, with reference to FIG. 30A. The continuous mode of operation of conserver 504 is described herein with reference to FIG. 14D. When second selector member 672 is moved to select a continuous mode of operation, first selector member 670 is rotated such that passage 760 is no longer in line with passage 616 of first body portion 512. As such, fluid cannot reach the back side 735 of demand piston 734 from fluid passage 616. Thus, biasing member 732 moves demand piston 734 in direction 750 which brings fluid passage 602 into fluid communication with fluid passage 588. Since, demand piston 734 is not moved in direction 752 due to a buildup of pressure on the backside of demand piston 734, the flow of fluid into passage 602 is continuous.

In an alternative embodiment, the pneumatic controller is replaced with an electronic controller which includes a processor with software or firmware configured to control the timing of the pulses and the duration of each pulse. The electronic controller still can use a trigger, such as a detection of the inhalation of the patient to start the intermittent flow of fluid and/or the detection of the absence of inhalation and/or the presence of exhalation of the patient to stop the intermittent flow of fluid.

In the illustrated embodiment shown in FIGS. 10-30, conserver 500 is able to operate in either an intermittent mode of operation or a continuous mode of operation for any of the selected fluid passages 416 of flow selector 400 because the flow selector 400 operates independent of first mode selector 670 and second mode selector 672 of the continuous or intermittent selector. By having the continuous or intermittent selector operate independent of flow selector 400, a low continuous flow, such as a flow corresponding to fluid passage 416 a may be implemented without the need to subject a patient to higher flow rates in order to select a continuous flow.

However, in some embodiments it is not desirable to provide a continuous flow of fluid to a patient at certain flow rates, particularly higher flow rates. Referring to FIGS. 31-34, various components of conserver 500 are modified such that the ability to select continuous or intermittent modes of operation with the continuous or intermittent selector and/or flow rates with flow selector 400 is dependent on the current selection of the other of the continuous or intermittent selector and flow selector 400.

The modified conserver 500 includes an interlock 900 which connects flow selector 400 with one of first mode selector 670 and second mode selector 672 of the continuous or intermittent selector. Interlock 900 prevents the selection of a continuous mode of operation with the continuous or intermittent selector 670, 672 for one or more selections of fluid passages 416 of flow selector 400 and further prevents the selection of one or more selections of flow selector 400 while the continuous or intermittent selector 670, 672 is in the continuous mode of operation. It should be appreciated that interlock 900 may also be configured to prevent the selection of one or more flow selections when continuous or intermittent selector 670, 672 is in the intermittent mode of operation and/or the selection of the intermittent mode of operation for one or more flow selections of flow selector 400.

Referring to FIG. 31, a modified second body portion 512′ includes a cavity or opening 902 which extends from axial surface 664 of recess 667 through to alignment feature 634 (see FIG. 33) of modified second body portion 512′. A coupler 904 is positioned within cavity 902 and is able to move within cavity 902 such that an engagement surface 906 of coupler 904 is able to protrude out from surface 664 and into alignment feature 634. In one embodiment, coupler 904 is a pin having rounded ends. In another embodiment, coupler 904 is a plurality of spherical balls positioned in cavity 902, such as two spherical balls.

Referring to FIG. 32, a modified first mode selector member 670′ is shown. First mode selector 670′ includes a recess 908 having an engagement surface 910. Recess 908 is sized to receive a portion of coupler 904 such that engagement surface 906 of coupler 904 can engage engagement surface 910 of first selector 670′. When coupler 904 is received by recess 908 and coupler 904 is prevented from egressing from recess 908, first mode selector member 670′ is unable to move relative to second body portion 512′. As such, a user is unable to impart a rotation to second mode selector 672 causing the rotation of first mode selector 670′.

In the illustrated embodiment, recess 908 is positioned such that coupler 904 is received by recess 908 when continuous or intermittent selector is in the intermittent mode of operation. When continuous or intermittent selector is in the continuous mode of operation coupler 904 and recess 908 are not aligned and hence coupler 904 cannot advance into recess 908.

Referring to FIG. 34, a modified flow selector 400′ is shown. Flow selector 400′ includes a recess 914 having an engagement surface 916. Flow selector 400′ further includes a top surface 918 of ridge 481. Recess 914 is sized to receive a portion of coupler 904 such that engagement surface 906 of coupler 904 can engage engagement surface 916 of flow selector 400′. When coupler 904 is received by recess 914 and coupler 904 is prevented from egressing out of recess 914, the movement of flow selector 400′ is further limited. Illustratively, flow selector 400′ can only be moved to align adjacent fluid passages 416 a and 416 b with fluid passage 547 when coupler 904 is received by recess 914. As such, a user is unable to impart a rotation to flow selector 400′ to select another fluid passage besides, fluid passages 416 a and 416 b. In one embodiment, recess 914 is sized to only permit the alignment of a single fluid passage 416. In another embodiment, recess 914 is sized to permit the alignment of multiple spaced apart fluid passages 416 while blocking the selection of at least one intervening fluid passage 416.

In the illustrated embodiment, recess 914 is positioned such that coupler 904 is received by recess 914 when flow selector 400′ is oriented such that one of fluid passages 416A and 416B are aligned with fluid passage 547. When flow selector 400′ is oriented such that one fluid passages 416C-416F are aligned with fluid passage 547 coupler 904 and recess 914 are not aligned and hence coupler 904 cannot advance into recess 914.

The operation of interlock 900 is explained below with the aid of four examples. In a first example, flow selector 400′ is oriented such that fluid passage 416 b is aligned with fluid passage 547 and first mode selector 670′ of continuous or intermittent selector is in the orientation corresponding to the intermittent mode of operation. In this first example, a user desires to change conserver 500′ to a continuous flow and to maintain fluid passage 416B in alignment with fluid passage 547 which is a change permitted by interlock 900. As such, a user imparts a rotation to second mode selector 672 which in turn imparts a rotation to first mode selector 670′.

It should be noted that when first selector 670′ is oriented in the intermittent mode of operation, recess 908 and coupler 904 are aligned. In order for first selector 670′ to be rotated to the orientation corresponding to the continuous mode of operation, coupler 904 must be egressed out of recess 908. However, coupler 904 can only be egressed out of recess 908 when recess 914 of flow selector 400′ is aligned with coupler 904. If recess 914 and coupler 904 are not aligned, coupler 904 contacts surface 918 which prevents the egression of coupler 904 from recess 908.

However, in the example given coupler 904 and recess 914 are aligned. As such, the rotation imparted to first mode selector 670′ results in coupler 904 being egressed out of recess 908 such that engagement surface 906 of coupler 904 is now in contact with surface 671 of first selector 670′ and is advanced into recess 914 of flow selector 400′.

In a second example, flow selector 400′ is oriented such that fluid passage 416D is aligned with fluid passage 547 and first mode selector 670′ of continuous or intermittent selector is in the orientation corresponding to the intermittent mode of operation. In this second example, a user desires to change conserver 500′ to a continuous flow and to maintain fluid passage 416D in alignment with fluid passage 547 which is a change prohibited by interlock 900.

The user attempts to impart a rotation to second mode selector 672 which in turn would result in a rotation of first mode selector 670′. However, since flow selector 400′ is oriented such that fluid passage 416 d is aligned with fluid passage 547 recess 914 and coupler 904 are not aligned and coupler 904 is prevented from advancing into recess 914, but rather contacts surface 918. Therefore, coupler 904 cannot be egressed out of recess 908 and first selector 670′ cannot be rotated relative to second body portion 512′. The end result being that conserver 500′ cannot be changed to a continuous mode of operation in this example.

In a third example, flow selector 400′ is oriented such that fluid passage 416A is aligned with fluid passage 547 and first selector 670′ of continuous or intermittent selector is in the orientation corresponding to the intermittent mode of operation. In this third example, a user desires to change conserver 500′ such that it is still in an intermittent mode of operation and to place fluid passage 416D in alignment with fluid passage 547 which is a change permitted by interlock 900.

The user rotates flow selector 400′ to orient fluid passage 416D with fluid passage 547. Coupler 904 must egress from recess 914 in order for flow selector 400′ to be so oriented. Since conserver 500′ is in the intermittent mode of operation, recess 908 in first mode selector 670′ is aligned with coupler 904 and coupler 904 can be advanced into recess 908 as it is being egressed from recess 914.

In a fourth example, flow selector 400′ is oriented such that fluid passage 416A is aligned with fluid passage 547 and first mode selector 670′ of continuous or intermittent selector is in the orientation corresponding to the continuous mode of operation. In this third example, a user desires to change conserver 500′ such that it is still in a continuous mode of operation and to place fluid passage 416D in alignment with fluid passage 547 which is a change prohibited by interlock 900.

The user attempts to rotate flow selector 400′ to orient fluid passage 416D with fluid passage 547. Coupler 904 must egress from recess 914 in order for flow selector 400′ to be so oriented. Since conserver 500′ is in the continuous mode of operation, recess 908 in first mode selector 670′ is not aligned with coupler 904 and coupler 904 cannot be advanced into recess 908 as it is attempting to be egressed from recess 914. Therefore, the user is unable to rotate flow selector 400′ such that fluid passage 416D is aligned with fluid passage 547.

Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims. 

The invention claimed is:
 1. An apparatus for connection to a source of pressurized fluid and for connection to a cannula, the apparatus comprising: a revolved body having a first end, a second end, a central longitudinal axis, an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output; and a flow selector positioned between the input and the output, the flow selector being rotatably coupled to the revolved body at a location between the first end and the second end of the revolved body, the flow selector being actuatable from the exterior of the revolved body and positioned such that an axis of rotation of the flow selector is parallel to and offset from the central longitudinal axis of the revolved body, wherein the flow selector includes a first fluid passage configured to restrict the flow of fluid to a first flow rate from the input to the output when the first fluid passage is aligned with the fluid passage which connects the input and the output.
 2. The apparatus of claim 1, wherein the flow selector further includes a second fluid passage configured to restrict the flow of fluid to a second flow rate from the input to the output when the second fluid passage is aligned with the fluid passage connecting the input and the output, the first fluid passage and the second fluid passage each being alignable with the fluid passage by rotating the flow selector about its axis of rotation.
 3. The apparatus of claim 2, further comprising a detent coupled to one of the revolved body and the flow selector and configured to interact with the other of the revolved body and the flow selector to provide an indication of when one of the first fluid passage and the second fluid passage is aligned with the fluid passage.
 4. The apparatus of claim 3, further comprising an axle coupled to the revolved body and configured to support the flow selector, the axle including a central fluid passage which is in fluid communication with the fluid inlet passage.
 5. The apparatus of claim 1, wherein a portion of the fluid passage is generally aligned with the central longitudinal axis of the revolved body.
 6. The apparatus of claim 1, wherein an exterior surface of the revolved body defines an envelope of the revolved body and the flow selector is substantially contained within the envelope of the revolved body.
 7. The apparatus of claim 6, wherein the flow selector has a first radial extent, the flow selector being positioned so that at least a portion of the first radial extent extends outside the envelope of the revolved body.
 8. The apparatus of claim 7, wherein the flow selector has a second radial extent including an indicia corresponding to the alignment of the first fluid passage of the flow selector with the fluid passage of the revolved body, the second radial extent being less than the first radial extent and the flow selector being positioned so that the second radial extent is contained within the envelope of the revolved body, the revolved body including a window such that the indicia of the second radial extent is visible through the window when the first fluid passage of the flow selector is aligned with the fluid passage of the revolved body.
 9. An apparatus comprising: a device having a first fluid inlet in fluid communication with a first fluid outlet and a second fluid inlet in fluid communication with a second fluid outlet; a body member rotatably coupled to the device, the body member including a plurality of fluid passages, each fluid passage being selectably positionable in fluid communication with the first fluid inlet and the first fluid outlet by rotating the body member relative to the device, each fluid passage being configured to provide a respective flow rate of fluid from the first fluid inlet to the first fluid outlet when positioned in fluid communication with the first fluid inlet and the first fluid outlet; an axle coupled to the body member, the axle having a central fluid passage in fluid communication with the second fluid inlet and the second fluid outlet to provide a flow of fluid from the second fluid inlet to the second fluid outlet; and a knob coupled to the body member, the knob having an outer surface being actuatable from the exterior of the device, wherein the body member is positioned between the axle and the knob such that the knob overlaps the body member.
 10. The apparatus of claim 9, wherein at least a first of the plurality of fluid passages includes an occluder positioned within an opening formed in the body member to reduce the size of the first fluid passage and hence control the amount of fluid that is communicated from the first fluid inlet to the first fluid outlet when the first fluid passage is aligned with the first fluid inlet and the first fluid outlet.
 11. The apparatus of claim 10, wherein the first fluid passage is generally parallel to the axle and wherein the occluder is received in an opening that intersects with the first fluid passage.
 12. An apparatus for coupling a first fluid inlet of a device to a first fluid outlet of the device and a second fluid inlet of the device to a second fluid outlet of the device, the apparatus comprising: a body member rotatably coupled to the device, the body member including a plurality of fluid passages, each fluid passage being selectably positionable in fluid communication with the first fluid inlet and the first fluid outlet by rotating the body member relative to the device, each fluid passage being configured to provide a respective flow rate of fluid from the first fluid inlet to the first fluid outlet when positioned in fluid communication with the first fluid inlet and the first fluid outlet; an axle coupled to the body member, the axle having a central fluid passage in fluid communication with the second fluid inlet and the second fluid outlet to provide a flow of fluid from the second fluid inlet to the second fluid outlet, wherein at least a first of the plurality of fluid passages includes an occluder positioned within an opening formed in the body member to reduce the size of the first fluid passage and hence control the amount of fluid that is communicated from the first fluid inlet to the first fluid outlet when the first fluid passage is aligned with the first fluid inlet and the first fluid outlet, the first fluid passage is generally parallel to the axle and wherein the occluder is received in an opening that intersects with the first fluid passage, and the opening is generally radial to the first fluid passage and the occluder is a ball.
 13. An apparatus for connection to a source of pressurized fluid and for connection to a cannula for communication of fluid to a patient, the apparatus comprising: a body having an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output; and a pneumatic controller including a valve assembly in communication with the fluid passage of the body, the pneumatic controller being configured to detect an inhalation of the patient and to provide a series of at least two pulses of the fluid to the output during the inhalation of the patient, the pneumatic controller providing an initial pulse having a fluid amplitude greater than a fluid amplitude of subsequent pulses in the series of at least two pulses without the aid of a fluid reservoir separate from the fluid passage of the body.
 14. The apparatus of claim 13, wherein the fluid passage of the body includes a seat for receiving a seal, and the pneumatic controller includes a piston moveably coupled to the body and configured to move between a first position preventing the passage of fluid to the outlet and a second position permitting the passage of fluid to the outlet, the movement of the piston between the first position and the second position being controlled to provide the at least two pulses of the fluid to the outlet, wherein a first portion of the piston contacts and cooperates with the seal to prevent the passage of fluid to the outlet in the first position and wherein the first portion is spaced apart from the seal to permit the passage of fluid to the outlet in the second position.
 15. The apparatus of claim 14, wherein the piston includes a seat surface for sealing against the seal when the piston is in the first position, the piston being biased toward the second position by a biasing member.
 16. The apparatus of claim 15, wherein the body further includes a second fluid passage receiving fluid from the input and providing fluid to a cavity partially bounded by the piston and wherein an accumulation of fluid in the cavity biases the piston to the first position against the biasing force of the biasing member.
 17. The apparatus of claim 16, further comprising a vent fluid passage connected to the cavity and to atmosphere and a diaphragm coupled to the body and moveable between a first position preventing the flow of fluid from the cavity to atmosphere through the vent passage and a second position permitting the flow of fluid from the cavity to atmosphere through the vent passage, the diaphragm being biased toward the first position by a diaphragm biasing member.
 18. The apparatus of claim 17, wherein the output is in fluid communication with a first side of the diaphragm through a sense fluid passage and wherein the presence of an inhalation of the patient reduces an effective force of the diaphragm biasing member.
 19. The apparatus of claim 18, wherein a combination of the accumulation of fluid in the cavity and the reduction of the effective force on the diaphragm biasing member results in the diaphragm being moved toward the second position thereby permitting the passage of fluid from the cavity to atmosphere.
 20. The apparatus of claim 19, wherein the passage of the accumulated fluid to atmosphere results in the movement of the piston to the second position permitting the flow of fluid to the outlet, and wherein once a first portion of the accumulated fluid has left the cavity the diaphragm returns to the first position and the piston is moved toward the first position due to further accumulation of fluid in the cavity.
 21. The apparatus of claim 13, wherein the cannula is a single lumen cannula.
 22. The apparatus of claim 13, wherein the series of pulses are sinusoidal pulses.
 23. The apparatus of claim 13, wherein the pneumatic controller is configured to provide a continuous flow of fluid to the outlet by maintaining the piston in the second position.
 24. The apparatus of claim 13, wherein the controller compensates for at least one of breath depth and breath length to reduce an oxygen saturation recovery time for the patient.
 25. The apparatus of claim 24, wherein the recovery time is less than one minute.
 26. The apparatus of claim 24, wherein the recovery time is about 35 seconds.
 27. An apparatus for providing fluid from a source of pressurized fluid to a patient, the apparatus comprising: a single lumen cannula configured to be received by the nostrils of the patient; a body having an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output; a flow selector having at least a first fluid passage configured to provide a first restricted fluid flow rate and a second fluid passage configured to provide a second restricted fluid flow rate, each of the first fluid passage and the second fluid passage being selectably positionable in the fluid passage of the body between the input and the output; and a controller configured to detect a first trigger corresponding to a beginning portion of an inhalation of the patient and a second trigger corresponding to one of an ending portion of the inhalation of the patient and an exhalation of the patient, the controller being further configured to provide fluid to the cannula through the output between the detection of the first trigger and the detection of the second trigger in a first mode of operation and continuously in a second mode of operation.
 28. The apparatus of claim 27, wherein the controller is a electronic controller.
 29. The apparatus of claim 27, wherein the controller is a pneumatic controller.
 30. The apparatus of claim 27, wherein the controller is further configured to provide at least two pulses of fluid between the detection of the first trigger and the detection of the second trigger.
 31. The apparatus of claim 27, wherein the controller is further configured to provide at least three pulses of fluid to the controller between the detection of the first trigger and the detection of the second trigger.
 32. The apparatus of claim 27, wherein the ending of the inhalation corresponds to the second trigger.
 33. The apparatus of claim 27, wherein the exhalation of the patient corresponds to the second trigger.
 34. The apparatus of claim 27, wherein the first trigger and the second trigger are sensed through the single lumen cannula.
 35. An apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient, the apparatus comprising: a body having an input adapted to be coupled to the source of pressurized fluid, an output adapted to be coupled to the cannula, and a fluid passage configured to connect the input to the output; a flow selector having at least a first fluid passage configured to provide a first restricted flow rate of fluid and a second fluid passage configured to provide a second restricted flow rate of fluid, each of the first fluid passage and the second fluid passage being positionable in the fluid passage of the body between the input and the output to provide a first flow setting and a second flow setting respectively, the flow selector being positionable in the first flow setting or the second flow setting by an operator from an exterior of the body; a controller configured to provide fluid to the cannula based on the respective flow setting of the flow selector, the controller being operable in two modes of operation, a continuous mode of operation wherein fluid is provided to the cannula in a continuous flow and an intermittent mode of operation wherein the fluid is provided to the cannula as at least three pulses of fluid during a respective inhalation of the patient; and a mode selector accessible from the exterior of the body and actuatable by an operator independent of an actuation of the flow selector, the mode selector having a first mode setting and a second mode setting, the mode selector being operably coupled to the controller and configured such that the first mode setting configures the controller to operate in the continuous mode of operation and the second mode setting configures the controller to operate in the intermittent mode of operation.
 36. The apparatus of claim 35, wherein the controller is a pneumatic controller and is configured to detect a first trigger corresponding to a beginning portion of the respective inhalation of the patient and a second trigger corresponding to one of an ending portion of the respective inhalation of the patient and an exhalation of the patient, the at least three pulses of fluid only being provided during a timeframe between the first trigger and the second trigger.
 37. The apparatus of claim 35, wherein the apparatus further comprises an interlock operably coupled to the mode selector and operably coupled to the flow selector, the interlock configured to prevent the selection of the first mode setting with the mode selector when the flow selector is positioned in the second flow setting and to permit the selection of the first mode setting with the mode selector when the flow selector is positioned in the first flow setting.
 38. The apparatus of claim 37, wherein the interlock is further configured to prevent the selection of the second flow setting with the flow selector when the mode selector is positioned in the first mode setting and to permit the selection of the second flow setting with the flow selector when the mode selector is positioned in the second mode setting.
 39. An apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient, the apparatus comprising: a body having an input adapted to be coupled to the source of pressurized fluid, an output adapted to be coupled to the cannula, and a fluid passage configured to connect the input to the output, the fluid passage including a seat for receiving a seal; a flow selector having at least a first fluid passage configured to provide a first restricted flow rate of fluid and a second fluid passage configured to provide a second restricted flow rate of fluid, each of the first fluid passage and the second fluid passage being positionable in the fluid passage of the body between the input and the output; and a pneumatic controller including a piston moveably coupled to the body and configured to move between a first position preventing the passage of fluid to the outlet and a second position permitting the passage of fluid to the outlet, the movement of the piston between the first position and the second position being controlled to provide an intermittent flow of fluid to the outlet, wherein a first portion of the piston contacts and cooperates with the seal to prevent the passage of fluid to the outlet in the first position and wherein the first portion is spaced apart from the seal to permit the passage of fluid to the outlet in the second position.
 40. The apparatus of claim 39, wherein the first portion of the piston is tapered to aid in centering the first portion relative to the seal.
 41. The apparatus of claim 39, wherein the controller is further configured detect a first trigger corresponding to a beginning portion of an inhalation of the patient and a second trigger corresponding to one of an ending portion of the inhalation of the patient and an exhalation of the patient, the controller being further configured to provide fluid from the flow selector to the cannula through the output only between the detection of the first trigger and the detection of the second trigger.
 42. An apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient, the apparatus comprising: a body having an input adapted to be coupled to the source of pressurized fluid and an output adapted to be coupled to the cannula and a fluid passage configured to connect the input to the output, the body including at least three body portions which when assembled form the body, the at least three body portions being keyed to permit the assembly of the body portions in a single orientation; a coupler configured to couple the at least three body portions together; a flow selector coupled to the body and positioned such that an outer surface of the flow selector is actuatable by an operator, the outer surface of the flow selector being positioned between a first end of the body and a second end of the body, the flow selector having at least a first fluid passage configured to provide a first restricted flow rate of fluid and a second fluid passage configured to provide a second restricted flow rate of fluid, each of the first fluid passage and the second fluid passage being positionable in the fluid passage of the body between the input and the output; and a controller configured to provide fluid to the output at least in an intermittent mode of operation, wherein the fluid is provided as multiple pulses of fluid during an inhalation of the patient.
 43. The apparatus of claim 42, wherein the coupler includes a plurality of couplers, the first body portion includes a plurality of threaded openings each configured to threadably receive one of the plurality of couplers, the remaining of the at least three body portions including a plurality of openings configured to receive the plurality of couplers and positioned to align with the plurality of threaded openings when the body portions are arranged in the single orientation.
 44. An apparatus for connection to a source of pressurized fluid and for connection to a cannula for delivery of fluid to a patient, the apparatus comprising: a body having an input adapted to be coupled to the source of pressurized fluid and an output configured to be coupled to the cannula and a fluid passage configured to connect the input to the output, the body being a revolved body about a first axis; a flow selector rotatable coupled to the body and having a first outer surface at least partially concealed within the revolved body, the flow selector including a plurality of fluid passages, each of the plurality of fluid passages being configured to restrict the flow of fluid from the input to the output by a respective amount when the respective fluid passage is aligned with the fluid passage, wherein the selection of a first fluid passage from the plurality of fluid passages is performed by a rotation of the flow selector, the rotation being imparted by an operator applying a force to a portion of the first outer surface of the flow selector which is accessible from an exterior of the body, wherein an exterior of the body defines an envelope of the body and the flow selector is substantially contained within the envelope of the body, wherein the flow selector has a first radial extent including the portion of the first outer surface of the flow selector, the flow selector being positioned so that at least the portion of the first radial extent extends outside the envelope of the body and a second radial extent including an indicia corresponding to the alignment of the first fluid passage with the fluid passage, the second radial extent being less than the first radial extent and the flow selector being positioned so that the second radial extent is contained within the envelope of the body, the body including a window such that the indicia of the second radial extent is visible through the window when the first fluid passage is aligned with the fluid passage.
 45. An apparatus for use with a fluid apparatus, the fluid apparatus including a body having an interior cavity, a fluid inlet which is configured to receive a high pressure fluid from a source of pressurized fluid, and an application device which utilizes fluid at a lower pressure, wherein the apparatus is configured to provide fluid for the application device at the lower pressure, the apparatus comprising: a base member adapted to be received within the interior cavity of the fluid apparatus, the base member including a base portion and a guide portion extending from the base portion, the base member having a central passageway extending there through, the central passageway being positioned such that it is in fluid communication with the fluid inlet of the fluid apparatus; a piston adapted to be received within the interior cavity of the fluid apparatus, the piston including a piston base portion and a stem portion, the stem portion being configured to be received by the central passageway in the guide portion of the base member, the piston having a fluid passageway there through with a fluid inlet in the stem portion and a fluid outlet in the piston base portion, the fluid outlet being in fluid communication with the application device; and a spring sized to receive the guide portion of the base member, a first end of the spring being positioned adjacent the base portion of the base member and a second end of the spring being positioned adjacent a seat surface of the piston base portion, the seat surface being located in a recess of the piston base portion, the recess being sized to receive a first end of the guide portion of the base member.
 46. The apparatus of claim 45, further comprising a housing which is adapted to be received within the interior cavity of the fluid apparatus, the housing including an interior cavity and wherein the base member, the piston, and the spring are generally positioned within the interior cavity of the housing.
 47. The apparatus of claim 46, further comprising a first seal positioned generally between a seat surface of the interior cavity of the body of the fluid apparatus and the base member, the first seal being received within a half dovetailed groove in the body portion of the fluid apparatus.
 48. An apparatus for providing fluid from a source of pressurized fluid to a cannula for communication to a patient, the apparatus comprising: a body having an input adapted to be coupled to the source of pressurized fluid, an output configured to be coupled to the cannula, and a fluid passage configured to connect the input to the output; a pneumatic controller being operable in two modes of operation, a continuous mode of operation wherein fluid is provided to the cannula in a continuous flow and an intermittent mode of operation wherein the fluid is provided to the cannula as multiple pulses of fluid within a time period generally between the detection of a first trigger and a second trigger; and a mode selector accessible from the exterior of the body and actuatable by an operator, the mode selector having a first mode setting and a second mode setting, the mode selector being operably coupled to the pneumatic controller and configured such that the first mode setting configures the pneumatic controller to operate in the continuous mode of operation and the second mode setting configures the pneumatic controller to operate in the intermittent mode of operation.
 49. The apparatus of claim 48, wherein the multiple pulses are provided throughout the time period.
 50. The apparatus of claim 48, wherein the first trigger corresponds to a beginning of an inhalation of the patient and the second trigger corresponds to one of an ending of the inhalation of the patient or an exhalation of the patient.
 51. The apparatus of claim 50, wherein the multiple pulses are provided throughout the time period. 